Evaluating and preventing the tsunami risk for France's metropolitan and overseas coasts
https://www.senat.fr/opecst/english_report_tsunami/english_report_tsunami_mono.htmlSENAT
Report n° 117 (2007-2008) by M. Roland COURTEAU, Senator (for the parliament office for the evaluation of scientific and technological choices) - Appendix to the minutes of the 7 December 2007 session
- INTRODUCTION
- I. WHAT IS A TSUNAMI?
- II. A MANAGEMENT OF THE TSUNAMI RISK WHICH VARIES DEPENDING ON THE BASINS
- A. A RISK TAKEN INTO CONSIDERATION FOR THE PAST SEVERAL DECADES IN THE PACIFIC
- B.
A RISK THAT BEGAN TO BE TAKEN SERIOUSLY IN THE OTHER
BASINS FOLLOWING THE TSUNAMI OF 26 DECEMBER 2004
- A. A RISK TAKEN INTO CONSIDERATION FOR THE PAST SEVERAL DECADES IN THE PACIFIC
- III.
FRANCE'S POSITION: A WAIT-AND-SEE POLICY THAT IS
UNACCEPTABLE CONSIDERING THE SERIOUSNESS OF THE STAKES
- A. A HIGH VULNERABILITY TO TSUNAMIS WHICH SHOULD INDUCE FRANCE TO MAKE A STRONG COMMITMENT
- 1. Important security stakes
- 2. Significant advantages
- 3. A strong mobilization following the Sumatra tsunami
- 1. Important security stakes
- B.
A MOVEMENT THAT IS RUNNING OUT OF STEAM, DUE TO THE
LACK OF A STRATEGIC VISION AND INSUFFICIENT FUNDING
- A. A HIGH VULNERABILITY TO TSUNAMIS WHICH SHOULD INDUCE FRANCE TO MAKE A STRONG COMMITMENT
- IV. RECOMMENDATIONS: FOR A STRATEGIC VISION OF TSUNAMI-RISK MANAGEMENT
- A. SIGNIFICANT STAKES
- B. THE RECOMMENDATIONS
- 1. Two introductory remarks
- 2. The structural recommendations
- 3. Basin-specific proposals
- 1. Two introductory remarks
- A. SIGNIFICANT STAKES
- I. WHAT IS A TSUNAMI?
- SUMMARY OF PROPOSALS
- CONCLUSION
- APPENDICES
- APPENDIX 2 -
LIST OF PERSONS INTERVIEWED
N° 488
NATIONAL ASSEMBLY
CONSTITUTION OF 4 OCTOBER 1958
THIRTEENTH TERM
|
N° 117
SENATE
REGULAR MEETING OF 2007-2008
|
Registered with the Presidency of the National Assembly
on 7 December 2007 |
Appendix to the minutes of the
7 December 2007 session |
PARLIAMENT OFFICE FOR THE EVALUATION OF
SCIENTIFIC AND TECHNOLOGICAL CHOICES (OPECST)
REPORT
on
Evaluating and preventing the tsunami risk for
France's metropolitan and overseas coasts
France's metropolitan and overseas coasts
by
M. Roland COURTEAU, Senator
Filed with the Bureau of the National Assembly
by Mr Claude BIRRAUX
First Vice-Chairman of the OPECST
|
Filed with the Senate Bureau
par M. Henri REVOL
Chairman of the OPECST
| ||||
INTRODUCTION
The Parliamentary Office for the Evaluation of Scientific
and Technological Choices (OPECST) has already had the
opportunity to examine the subject of natural risks and their
prevention, thanks to the work carried out by our colleague, Mr. Christian Kert, Deputy, author of two benchmark reports, the first of which1(*) dealt with earthquakes and ground movements and the second of which2(*) dealt with other natural hazards: hazards due to the weather, avalanches, inundations, droughts, forest fires, volcanism, collapsing mines and underground cavities.
In addition, following the dramatic Indonesian tsunami of
26 December 2004, our colleague, Mr. Christian Kert,
organized public hearings before the National
Assembly on 17 February 2005. These hearings were again held on
18 March 2005 in Port-la-Nouvelle (in the Aude département),
in cooperation with your rapporteur and our colleague Mr.
Jacques Bascou, Deputy. This work shined a light on a risk that
had up until then generated little concern in France. These
hearings also allowed us to take stock of the situation with
regard to tsunami-detection research and international
cooperation in the field of tsunami prevention and early-warning
systems.
On 22 March 2005,
the OPECST was commissioned to prepare a report by the Bureau
of the National Assembly, in accordance with Article 6 (section
B) of edict no. 58-1100 of 17 November 1958 concerning
earthquake- and tidal wave-related hazards in the Mediterranean
Sea. Your rapporteur was put in charge of this study, the title
of which was later modified following the feasibility study.
The title of the study was modified following the presentation of the feasibility study.
Firstly, the term "tidal wave" turned out to be
inappropriate, since it refers to a meteorological phenomenon,
while tsunamis are always seismic in origin.
Secondly, an analysis of the tsunami risk limited to the
Mediterranean area proved too narrow in scope, in so far as
tsunamis can occur in any large ocean basin and France is
present in every ocean of the world, via its overseas départements and territories.
The final report therefore deals with evaluating and
preventing the risk posed by tsunamis to all French coasts, both
in metropolitan France and overseas.
Your rapporteur first examined in detail the
characteristics of this hazard and concluded that in order to
decrease our vulnerability to tsunamis, a sophisticated
early-warning system must be established.
Indeed, tsunamis are relatively rare phenomena compared to
other natural events, such as storms and inundations;
however, they often have a devastating impact on coastal
populations. As a result, their prevention (or, at the very
least, the limitation of their impact) demands a dense system of
instruments for measuring earthquakes and sea level, a
dependable, high-speed data-transmission system, and a
preestablished, operational plan for alerting the concerned
populations. The effectiveness of any early-warning system
ultimately depends upon an informed, aware population, that must
also be able to adopt the appropriate responses.
These significant budgetary and logistical constraints,
combined with the fact that tsunamis most frequently occur in
the Pacific Ocean, have led to diverse measures for the
management of this risk. These measures vary according to the
particular ocean basin: while the Pacific states began to set up
an international warning system in the second half of the 20th
century, efforts to manage the tsunami risk in the other ocean
basins are much more recent and directly linked to the shock of
the tsunami of 26 December 2004.
On the one hand, it was necessary to recognize the
vulnerability of all the oceans and seas. Statistically
speaking, the Indian Ocean is considered the safest (large)
ocean basin with regard to tsunamis, since it accounted for only
4% of tsunamis generated during the 20th century. However, the
2004 tsunami claimed more victims than all other (known)
tsunamis combined since ancient times.
On the other hand, it was necessary to explain to the
concerned governments that, even if the risk is rare, the public
no longer accepts to be left unprotected when a warning system
that saves human lives could be set up.
Under the aegis of the United Nations, it was therefore
decided in 2005 to create a tsunami warning system for the
Indian Ocean, the Caribbean and the Mediterranean/Northeast
Atlantic zone.
Two years
later, this project has achieved unequal results: while the
assessment is generally positive for the Indian Ocean, the
setting up of an early-warning system for the Caribbean and
Mediterranean/Northeast Atlantic zone has fallen far behind
schedule due to the wait-and-see policy of the concerned
countries.
Due to the
dispersal of its overseas territories, France is particularly
sensitive to the risk of tsunamis. Indeed, it began to set up
its tsunami warning system for French Polynesia in the 1960s.
Following the Sumatra tsunami, France pushed strongly for the
setting up of an early-warning system to cover the three other
ocean basins, particularly the Indian Ocean.
Nevertheless, it is clear that once the initial shock had
faded away, this movement quickly ran out of steam, due to a
lack of political will and insufficient funding. While the last
meeting dedicated to the setting up of an early-warning system
for the Mediterranean and the North Atlantic represented a real
break from the waiting game that France had been playing for
over a year, no concrete decision has yet been made and numerous
questions remain concerning the structure of the national
tsunami warning system, its geographical coverage and, above
all, the means it is to be allocated.
Your rapporteur will therefore make structural proposals
concerning the four ocean basins, as well as recommendations
for each sea/ocean, in order for France to quickly set up a
national tsunami warning centre for the Mediterranean, the
Caribbean and the Indian Ocean.
I. WHAT IS A TSUNAMI?
Your rapporteur would first like to consider in detail the
following questions: What is a tsunami? How are tsunamis
generated? How do they manifest themselves? How can this natural
phenomenon become a major risk for coastal populations?
A. A NATURAL HAZARD
Tsunamis are phenomena of geological origin, whose frequency varies depending on location.
1. A phenomenon of geological origin
If one excludes those very rare tsunamis generated by a
man-made explosion or the impact of a meteorite, it can be said
that tsunamis are always of geological origin.
They are caused by the sudden penetration or retreat (when
speaking of earthquakes, the terms "uplift", "upheaval",
"sinking" and/or "subsidence" are often used) of a large
quantity of geological material in the ocean depths, resulting
in the displacement of a large mass of water.
a) The different causes
Three natural phenomena are liable to cause a tsunami:
underwater and coastal earthquakes, landslides and volcanic
eruptions.
(1) Underwater earthquakes
On the surface, an earthquake manifests itself by ground
vibrations. It is caused by the fracturing of rocks deep below
the surface. This fracturing results from the release of a
great accumulation of energy, creating or reactivating faults3(*), when the rocks' rupture threshold has been reached.
The earth's crust is made up of several large lithospheric
plates which move about in relation to one another. While
the plates normally move from a few millimetres to a few
centimetres per year, in those regions on two plates boundary,
this movement is discontinuous. The faults can remain locked
during long periods of time, while the plates' regular movement
(convergence, divergence and sliding) continues. This locking of
the plate boundaries is the cause of local and regional
deformations, such as the buckling of the plates on either side
of the oceanic trenches.
In brief, the situation is as follows: the region of the
blocked fault is progressively deformed (slow elastic
deformation) as it accumulates energy, up until the time this
energy is suddenly released, resulting in a seismic rupture;
with the subsequent relaxing of the tectonic constraints, the
fault is once again blocked, and the same seismic cycle begins
all over again.
There are three types of fault line:
- Normal faults: the horizontal displacement provoked by
the slip corresponds to an extension of the crust (E), with
one of the blocks sinking downward relative to the second.
- Reverse faults: the horizontal displacement provoked by
the slip corresponds to a shortening of the crust (R), with
one of the blocks overlapping the second.
- Strike-slip faults: this third type of fault corresponds
to a horizontal shift along a vertical fault surface.
Source: IPGP
For a submarine earthquake to generate a tsunami, it must
result in a vertical movement of the sea floor. Therefore,
the hypocentre must be situated at a depth of less than 100 km.
In addition, it must have a magnitude of at least 6.5.
Subduction (or reverse-fault) earthquakes are particularly
dangerous, because the activated faults are often very long
and an earthquake's magnitude is proportional to this length, as
well as the seismic sliding along the fault line. The tsunami
that ravaged Indonesia on 26 December 2004 was provoked by an
earthquake with a magnitude of 9.3, which occurred off the
northwestern tip of the island of Sumatra. At this location, the
Indo-Australian Plate converges with and sinks below the
Eurasian Plate. The fault ruptured along 1,200 km. This rupture
lasted 9 minutes and caused water displacements of 15 to 25
metres. With a plate convergence speed of 6 cm/year in this
region, the last major earthquake would have taken place between
400 and 600 years ago.
Normal-fault earthquakes are provoked by much smaller fault
lines (with a maximum length of 200 to 300 km) and, therefore,
are of a weaker magnitude. However, since the angles are
generally steeper (30° to 40°, as compared to 10° to 20° for
subduction earthquakes), the tsunami risk is not negligible. The
underwater earthquake of 21 November 2004 with a magnitude of
6.3, which occurred some ten kilometres south of the Iles des
Saintes, generated a tsunami that hit Guadeloupe and
Martinique.
One could
easily suppose that strike-slip fault earthquakes do not
generate tsunamis, since the sliding is horizontal. However,
although the tsunami risk is, in fact, low, it still exists and
depends on the angle of the underwater fault. A perfect example
is the Izmit earthquake in Turkey, which provoked a local
tsunami.
(2) Landslides
The Bureau de Recherches Géologiques et Minières (BRGM)
defines a landslide as the shearing off and displacement of a
mass of loose or rocky ground along a rupture area, often
corresponding to a pre-existing discontinuity. Landslides are
provoked by a combination of factors, that can be:
- either permanent in other words, only slightly or not at
all variable over time (the nature and mechanical properties
of the materials, the presence of preferred fracture planes,
the ground slope, etc.);
-
or semi-permanent in other words, variable over time (the water
content of the materials, erosion at the bottom of the slope,
anthropic activity, earthquakes, the collapse of a volcano,
etc.).
Landslides have caused numerous tsunamis.
On 16 December 1979, a section of the Nice Airport
embankment fell into the sea. A few minutes later, after a
relative lowering of the sea level, a tsunami submerged the
coast and a wave with an estimated height of between 2.5 and 3.5
metres hit the beach of La Salis in Antibes.
There is little consensus over the supposed causes of this
tsunami. Two competing arguments point the finger at either
1) work being carried out to expand the Nice Airport or 2) the
natural geological instability of the coast aggravated by the
heavy rains which fell on the region a few days prior to the
incident.
The most recent
studies call attention to two landslides: the first landslide
(with a volume of 10 million m3) consisted of the collapsed airport embankment, while the second and much larger landslide (150 million m3) would have taken place off the shore of Nice.
What's more, on 13 September 1999, the collapse of a section of basalt cliff (between 2 and 5 million m3) on the island of Fatu Hiva in the Marquesas Islands provoked a tsunami that struck the village of Omoa.
Landslides can also be caused by collapsing volcanoes. On
30 December 2002, on the island of Stromboli, two landslides
of several million m3 of rock blocks and ashes
carried away the volcanic emissions that had accumulated since
28 December. Following a retreat of the sea, waves several
metres high struck the island, injuring 6 persons and causing
material damage.
While
tsunamis caused by landslides can be highly destructive, they
are geographically limited. Indeed, while the vertical
deformation can exceed several dozen metres, the horizontal
dimensions (generally a few hundred metres) rarely exceed a
dozen kilometres; for this reason, the resulting waves have
relatively short wavelengths.
(3) Volcanic explosions
Volcanic explosions can also produce tsunamis, by suddenly
sending an immense volume of rock into the sea.
The volcanic eruption on Santorini around 1650 B.C.
generated a devastating tsunami that some argue led to the
demise of the Minoan civilization. The tsunami is thought to
have struck the eastern Mediterranean coasts with waves
estimated at around forty metres high in the vicinity of the
island.
Likewise, the
volcanic explosion of Krakatoa, in Indonesia, on 27 August 1883
generated waves 41 metres high which destroyed villages located
along the Sunda Straight between the islands of Java and
Sumatra, claiming some 36,000 victims.
b) A description of the tsunami phenomenon
Following an earthquake, a landslide or a volcanic
eruption, the oceanic layer is disrupted, with an uplift and,
sometimes, a subsidence of up to several metres. The water
surface, acted upon by the forces of gravity, begins to
oscillate and waves are generated in every direction outward
from the source of origin.
The propagation of a tsunami
Source: CEA
In deep water, tsunamis move at very fast speeds (between
700 and 900 km/h in depths of between 4,000 and 7,000
metres), with very long wave lengths4(*)
(from 100 to more than 200 km). In comparison, a wind-generated
wave has a period of around 10 seconds and a length of some 150
m.
The energy of a tsunami
wave forms a moving wall from the surface to the bottom of the
sea, even in the deepest of waters. This energy corresponds to a
mechanical energy (or total energy) that is the sum of the
wave's kinetic energy (velocity) and potential energy (linked to
the height of the wave).
Out at sea, the waves' speed is very great; therefore, the
kinetic energy is also very great and the potential energy
very weak. For this reason - and because the waves' period is
very long (between a few minutes and several dozen minutes) -
the tsunami waves remain undetected by ships at sea.
However, as the waves near the coast, they are slowed down
by the rising sea bottom and a shift occurs between the
kinetic energy and the potential energy. The kinetic energy
decreases (the wave velocity falls to as low as 36 km/h), while
the potential energy increases, with the waves growing in height
and provoking a rapid rise of the sea level in harbours and
bays or an overflowing of the sea onto the coast: in other
words, a tsunami.
c) Various manifestations
When a tsunami arrives on the coast, it can manifest itself
in various ways, depending on the sources put in play. For
instance, the greater the amount of displaced water, the greater
the distance travelled by the tsunami, the greater the number
of concerned countries, and the greater the risk of destruction.
Scientists distinguish between 3 types of tsunami:
- local tsunamis,
which are unobservable over a hundred kilometres and are
generally provoked by earthquakes with a magnitude of between
6.5 and 7.5, by landslides and by volcanic eruptions;
- regional tsunamis,
which travel a distance of between 100 and 1,000 km and are
almost always generated by subduction earthquakes (with the
exception of the Santorini eruption of 1650 B.C.);
- tsunamis
that are capable of devastating coasts thousands of kilometres
from their source of origin are known as teletsunamis
and are almost always provoked by subduction earthquakes (with
the exception of the Krakatoa eruption of 1883). The most recent
teletsunami struck the Indian Ocean on 26 December 2004, but
one can also cite the tsunami of 1 November 1755 provoked by an
earthquake off the coast of Lisbon and which crossed the
Atlantic, as well as the tsunami of 22 May 1960 provoked by an
earthquake in Chile and which crossed the entire Pacific Ocean,
generating 5-metre-high waves on the Japanese coast 24 hours
later.
In addition,
tsunamis are affected by the coastal relief. While steep slopes
reflect waves, gentle slopes increase their amplitude. Likewise,
an island can be protected by its corral reef "breaking" the
waves. These "site effects" explain why the Tuamotu archipelago
are well protected from tsunamis, while the Marquesas Islands
are particularly vulnerable; they also explain why tsunamis
often have a greater impact on harbours and estuaries.
What are the concrete manifestations of a tsunami?
First of all, a tsunami can cause the sea to retreat far
from the coast, followed by its very rapid rise engendering
violent, destructive currents. The water's backward surge is
also very destructive, for both lightweight installations and
persons who find themselves being "sucked away".
Tsunami waves can be amplified by the coastal relief. This
is the case of rivers which penetrate deep inland, forming a
narrow gully through which the rushing water creates a tidal
bore.
Likewise, in closed
spaces such as harbours and bays, the waves will succeed one
another at 10- to 20-minute intervals, creating a successive
emptying-filling effect, with strong currents and eddies.
The particular vulnerability of harbours explains why
several boats were damaged in certain harbours along the French
Riviera following the earthquake in Boumerdès, Algeria on 21 May
2003 (although the news media incorrectly reported that the
French coasts had escaped unscathed). For example, in the port
of Théoule-sur-Mer, a significant, rapid rise in the
water level was observed, followed by a retreat which partially
"pumped" the harbour dry. In the harbour of Figueirette, the
water level dropped some 1.5 meters in all of the basins, with
very strong currents entering and leaving the harbour.
Finally, in extreme cases, the tsunami can manifest itself
by a series of giant waves capable of reaching heights of up
to several dozen metres. Their period (between 20 and 40
minutes) makes them particularly dangerous, because those
persons having escaped the first wave often think that the
danger has passed and so descend to the shore to observe the
damage and aid survivors.
What's more, the largest wave is rarely the first, but rather
one of the succeeding waves which, in addition to its own
potential energy, recovers the energy of a broken wave that is
returning to sea. In Banda Aceh, during the Sumatra tsunami of
2004, the first wave measured between 1.5 and 2 metres in
height, while the second reached a height of more than 30 metres
at certain points along the coast.
In the general consciousness, tsunamis are dangerous
because they are associated with waves several metres high
striking the coast and destroying everything in their path. In
reality, the destructive force of a tsunami has less to do with
the height of its wave (or waves) than with its velocity (30 to
40 km/h) and the quantity of water it is carrying, allowing it
to penetrate up to several hundred metres inland over flat
terrain without any natural obstacles (up to 5 km in Banda
Aceh). While a classic wave, with a period of up to a minute,
does not raise the water level for a sufficient amount of time
to penetrate very far inland, a tsunami wave results in an
increased water level for a period of between 5 and 30 minutes.
Therefore, it is the
quantity of water which determines the extent of inundationing
and the height of the "run-up", or the rise in the water level
above sea level.
Tsunami propagation on the coast
Source: CEA
2. A natural phenomenon of unequal geographical distribution
The most dangerous zones are those with the greatest
seismic activity: in other words, those zones where the tectonic
plates converge, either by subduction (with one plate sliding
beneath another) or collision.
Tectonic plate map
Source: CEA
Since
the beginning of the 20th century, 911 tsunamis have been
reported in the world (for an average of 9 per year). 98
tsunamis were characterized by waves of between 1 and 5 metres
(an average of 1 per year). 6 teletsunamis occurred with waves
of over 5 metres and a distance travelled of over 5,000 km.
a) A greater frequency in the Pacific
According to the information gathered by your rapporteur
during his hearings, of the 2,180 tsunamis recorded all over
the world between the years - 1650 (supposed date of the Thera
Volcano eruption on Santorini) and 2005, 59% occurred in the
Pacific, 25% in the Mediterranean, 12% in the Atlantic and 4% in
the Indian Ocean.
However,
the geographic distribution of tsunamis recorded over a long
period of time is not necessarily pertinent information, in so
far as the available historic data varies according to the
region. For instance, we have much more knowledge of past events
to have occurred in the Mediterranean area than in the West
Indies or the Pacific zone.
Therefore, it is preferable to limit our examination of
tsunami distribution to the 20th century, even if this period
of time is too short for us to be able to draw definitive
conclusions.
These
20th-century figures show that 77% of tsunamis were generated in
the Pacific, as compared to 9% in the Mediterranean, 10% in the
Atlantic and 4% in the Indian Ocean.
In addition, the 5 most important teletsunamis of the 20th century all occurred in the Pacific:
-
On 1 April 1946, an earthquake with a magnitude of 8.6 in the
Aleutian Islands (Alaska) provoked a tsunami that killed 165
persons and caused more than $26 million worth of damage (in
1946 terms);
- On 4
November 1952, an earthquake with a magnitude of 9.0 off the
Kamchatka Peninsula (Russia) generated a tsunami which claimed
no human victims;
- On 9
March 1957, an earthquake with a magnitude of 9.1 in the
Aleutian Islands provoked a tsunami which killed 5 people in
Hawaii, no less than 3,600 km away;
- On 22 May 1960, an earthquake with a magnitude of 9.5 off
the coast of Chile generated a tsunami which claimed 2,000
victims;
- Finally, on 28
March 1964, an earthquake with a magnitude of 9.2 in Alaska's
Prince William Sound generated a tsunami which killed 122
persons and provoked damages estimated at more than $106
million.
Tsunamis occur
most frequently in the Pacific Ocean due to the intense seismic
activity of the earth's crust in this region of the world. As
shown in the map below, it is on the "Ring of Fire" (chains of
volcanoes whose origin is directly related to the sinking plates
of the subduction zones) that one observes the strongest
earthquakes as well as the most active volcanoes.
Sources of tsunamis in the world
(2,180 events from - 1628 to 2005)
Source: International Tsunami Data Base (UNESCO)
That said, the other ocean basins remain vulnerable.
b) No ocean basin is safe from tsunamis
In the Mediterranean,
the collision between the African and Eurasian Plates makes
this region particularly prone to earthquakes and tsunamis. The
large tsunamis to have struck this area in the past are
relatively well known (see table below). Historically, it
appears that the most destructive source of origin is that of
the subduction zone located beneath the Hellenic Arc (Crete in
365 and Rhodes in 1303). The eastern Mediterranean is still
considered the most dangerous zone.
The most important Mediterranean tsunamis
Date
|
Place of origin
|
Remarks
|
ca. - 1650
|
Santorini
|
Tsunami generated by the eruption of the Thera
volcano, with a wave estimated at 40 m.
|
365
|
Crete
|
Tsunami generated by an earthquake with a magnitude
of around 8,5, with a wave estimated at 10 m.
|
373
|
Helike
|
Tsunami generated by an earthquake with a magnitude
of around 7, with a wave estimated at 10 m.
|
1303
|
Rhodes
|
Tsunami generated by an earthquake with a magnitude of around 8.
|
1365
|
Algiers
|
Tsunami generated by an earthquake with a magnitude of around 7.
|
1755
|
Lisbon
|
Tsunami generated by an earthquake with a magnitude
of around 8, with a wave estimated at 4 m.
|
1908
|
Messina
|
Tsunami generated by an earthquake with a magnitude
of around 7, with a wave of 8 m.
|
The northeast Atlantic
seems less prone to tsunamis. However, the tsunami of 1
November 1755 off the coast of Lisbon was one of the most
destructive ever recorded anywhere in the world, with
5-metre-high waves striking the harbour and killing 20,000
persons.
The West Indies,
characterized by significant volcanic and seismic activity,
also run the risk of tsunamis. The West Indies are affected by
tsunamis generated in either the Caribbean or the Atlantic
(subduction earthquakes or teletsunamis).
According to a 2001 study by Narcisse Zahibo and Efim
Pelinovsky, around 24 tsunamis have been reported in the Lesser
Antilles over the past 400 years.5(*)
Finally, the Indian Ocean
is not safe from tsunamis, either. While it is true that the
area accounts for only 4% of recorded tsunamis, following the
Sumatra catastrophe, the tsunami risk can no longer be ignored
in this region. What's more, 3 large tsunamis have since been
provoked by strong earthquakes on 28 March 2005, 17 July
2006 and 12 September 2007.
B. THE TSUNAMI RISK
Tsunami hazard and tsunami risk are different. Tsunami risk
represents a potential danger which, if and when it occurs,
can have catastrophic results.
1. The risk factors
In environmental terms, risk can be defined as "the
possibility that an event occurs which is likely to disrupt the
natural equilibrium". Risk results from the combination of three
factors: 1) a hazard, 2) stakes and 3) the stakes'
vulnerability to the hazard.
a) The hazard
The "hazard" represents the source of danger. To evaluate
the risk, it is necessary to determine the hazard's
probability of occurrence, as well as its intensity and
frequency. However, the risk is not limited to the hazard alone.
For instance, a tsunami generating a 3-metre-high wave on a
desert island represents a minor risk; however, if the same wave
were to strike the beaches at Antibes (French Riviera) on a
national holiday in the middle of July, the results would be
dramatic. Therefore, the notion of risk is linked to the notion
of what is at stake.
b) The stakes
The "stakes" are those persons, property, facilities and/or
environments threatened by the hazard and likely to suffer
damage should it occur. These stakes can be divided into five
separate categories:
- the human stakes;
- the economic and financial stakes which concern
commercial, craft, industrial, agricultural and tourist
activities;
- the social
stakes, which include everything that affects social cohesion
and the functioning of society;
- the environmental stakes, which cover the possible damage to ecosystems and biodiversity;
- the heritage stakes, which concern historical and cultural monuments and a region's "public image".
These stakes can suffer varying degrees of damage, depending on the hazard's intensity:
- physical injuries to persons;
- structural damage to the urban fabric, to goods and property and to networks;
- functional damage disrupting day-to-day activities (cut
telephone and gas lines, power outages, disrupted modern
communication networks such as the Internet);
- environmental damage to the ecosystem;
- damage to the historical and cultural heritage.
c) Vulnerability
The hazard's capacity to damage the stakes varies according
to their vulnerability. Faced with a tsunami, a few simple
actions can save lives: a strong shaking and a retreating sea
are forerunners of a tsunami and should incite people to leave
the coast and seek refuge in buildings above the third floor.
The Sumatra tsunami of 26
December 2004 is a case in point: many lives would have been
saved if the concerned populations had had a basic understanding
of this hazard. We could have spared ourselves these horrible
images of the receding sea, the large waves already forming on
the horizon and numerous tourists in the process of gathering
shells or watching the approach of the oncoming waves. In
this case, the population was made all the more vulnerable for
its not having been properly informed.
Being vulnerable means being physically exposed to a hazard
and presenting a certain fragility to the catastrophe that
could occur. Vulnerability can vary over time, since its depends
principally on human activity. Today, the world's population is
particularly vulnerable to tsunamis due to densely inhabited
coastlines.
Indeed, the
transportation revolution and a globalized economy have greatly
increased international trade flows and pushed industry to the
coast, resulting in increased harbour traffic and the creation
of vast industrial harbour areas. Likewise, tourist and
leisure-activity development is concentrated on the coasts. The
rapid development of these activities has led to the massive
urbanization of the concerned coastlines.
The following figures allow for a quantification of this "coastalizing" trend.
Today, nearly half of Europe's population lives within 50
kilometres of the continent's 70,000 kilometres of coastline
(nearly 40% of the world's population lives within 100
kilometres of the coast). Average population density in France
is slightly higher than 100 inhabitants per square kilometre;
however, this figure rises to over 250 inhabitants for the
coastal districts and is over 600 for the
Provence-Alpes-Côte-d'Azur region.
In addition, the mountainous relief of volcanic islands -
as much in the Pacific as in the Indian Ocean and the
Caribbean - concentrates these islands' populations along the
coast.
One must not
underestimate the subjective component of vulnerability linked
to how the threat is perceived. Risk only exists when the social
group or individual considers it or himself as being "fragile"
faced with a given natural phenomenon. Different groups react
differently to the same event: while some do not recognize the
existence of any danger, others do but accept to live with it,
while still others refuse to accept it.
In the developed world, our notion of risk has evolved from
a fatalistic vision of risk as something divinely
determined (and so largely unaffected by human-based protective
measures) to the notion of managed risk (and, consequently, a
right to protection).
One
might think that in the case of natural risks, the question of
"responsibility" is irrelevant. However, recent changes in our
understanding of risk and responsibility demonstrate that, in
fact, this is not the case and increasingly society is looking
to protect itself against these "natural" risks. The creation of
legal and institutional structures, such as risk-prevention
agencies and policies (the establishment of
earthquake-construction standards, for example) illustrates the
desire of governments to both protect their citizens and limit
their liability in the event of a catastrophe.
2. Managing risk
As stated earlier, risk necessitates a vulnerability to the
natural hazard. Managing risk, therefore, entails a better
understanding of the hazard in question, as well as a reduction
of the concerned societies' vulnerability vis-à-vis the said
hazard through the establishment of an operational early-warning
system.
a) A better understanding of the hazard
Since reducing the frequency of tsunamis is not an option,
we must instead work to reduce their possible impact by
better understanding both the processes that provoke tsunamis
and their mechanisms of propagation, followed by the setting up
of an appropriate protection system.
Therefore, a better understanding of the hazard means being
capable of not only understanding the phenomenon (how it
manifests itself, its frequency and intensity, and the area
affected), but also predicting it (in other words, specifying
where and when it will occur).
As will be shown, understanding the hazard in order to
consider the risk necessitates our calling upon diverse
scientific fields, such as seismology, geography, oceanography,
geology and biology.
As
it turns out, it is essential to collect data allowing for a
better understanding of the hazard's characteristics.
To do this, we must rely upon not only eyewitness accounts and
photographs, but also hydraulic and geographic records in order
to determine the run-up level and the areas inundationed. That
is why post-tsunami surveys are so important, for they allow for
a close, reliable examination of the hazard, especially in
sparsely populated regions.
Tsunami-mapping in French Polynesia rests, to a large
extent, on meticulous observations made by scientists in the
aftermath of a tsunami.
Understanding tsunamis also depends upon a correct understanding
of their causes: earthquakes, landslides and volcanic
eruptions. The data that must be collected is two-fold:
- On the one hand, data directly linked to a specific event
(the localization and magnitude of a tsunami-generating
earthquake, the localization of a landslide and the volume of
displaced rocks, the localization of a volcanic eruption and the
volume of rocks either expelled or displaced following the
volcano's collapse, etc.); this information allows for a better
understanding of the phenomenon.
- On the other hand, a more global understanding of the
causes of tsunamis and their localization via the study of
faults, active volcanoes and instable rocky zones along the
seashore or underwater. For example, studying tsunami
directivity allows scientists to better determine the concerned
zones. Indeed, while a tsunami will spread outward in all
directions from its source of origin, a large amount of its
energy will propagate in a direction perpendicular to the fault
zone. As a result, the longer the earthquake's rupture area, the
greater the number of concerned zones. In addition, a zone
outside the tsunami's angle of maximum energy will be relatively
safe, even if located near the source of origin, while a zone
within the angle of maximum energy will receive the full force
of the tsunami, even if located thousands of kilometres away.
Therefore, this data facilitates the prediction and mapping
of tsunamis.
Insofar as
the hazard is characterized by its intensity and frequency, it
is important to have access to long series of data and to
reconstruct and determine the scale of past events. To this end,
several historical catalogues have been drawn up:
- An American catalogue covering the entire globe,
established by the National Geophysical Data Center, part of the
United States Department of Commerce's National Oceanic and
Atmospheric Administration (NOAA6(*));
- Two Russian catalogues, one covering the Pacific zone and
the other the Mediterranean zone, established by the
Russian Academy of Sciences;
- A European catalogue, financed by the European Commission
within the framework of the Fifth Research Framework Programme,
entitled The Genesis and Impact of Tsunamis on European Coasts (2001);
- An Italian catalogue;
- Studies concerning the West Indies carried out by
O'Loughlin and Lander (2003), Lander et al. (2002), and Zahibo
and Pelinovsky (2001).
It
should be pointed out that this task proves to be quite
difficult for ancient (and, sometimes, even recent) events,
insofar as there exists little direct data and the events must
be reconstructed from diverse documents (written texts,
eyewitness accounts, photographs or drawings). This historical
work is quite delicate and demands both a critical examination
of the sources and a verification of the data's coherency, in
order to use the information in the most pertinent and reliable
manner. In addition, this work is never completed, since
technological advances and the discovery of new sources are
liable to provide additional information.
It is in this context that computer simulations play an important role.
Firstly, they allow scientists to test various hypotheses
concerning the triggering and propagation of tsunamis.
The Nice tsunami of 16 October 1979 is a case in point:
because simulations showed that the landslide observed in the
area of the airport extension was insufficient to explain the
magnitude of the observed waves, the scientists directed their
research towards a second, much larger landslide. This
hypothesis was later confirmed by underwater observations.
Likewise, simulations can be used to complement in situ
observations and refine tsunami maps. For example, in French
Polynesia, several simulations were carried out in the most
vulnerable bays, in certain harbours and in the area of the
airport, in order to best determine those areas concerned by
tsunamis. Taking into account the population density along the
coast, it is difficult for the Polynesian authorities to set
strict regulations with regard to construction; they therefore
opt for a precise delimitation of the evacuation zones.
Secondly, simulations allow scientists to "test" tsunamis
in the zones considered vulnerable, but which lack reliable
observations. Therefore, these simulations allow us to predict a
possible tsunami, to determine its potential intensity and to
take the appropriate precautionary measures. These simulations
have the added advantage of being able to make decisions in the
case of a tsunami without having to wait for a confirmation of
the risk. Such simulations are all the more useful for those
tsunamis endangering nearby zones, thereby greatly reducing the
reaction time available.
To clarify, let us consider the following example: Suppose
that an earthquake of magnitude 7.5 occurs off the coast of
Japan. Taking into account its magnitude and its location at
sea, there is a strong chance that the earthquake provokes a
tsunami. However, in order to predict its amplitude and the
height of the waves that will strike the coast, scientists must
have instruments for measuring sea level (tsunamimeters) out at
sea. If there are not enough of these instruments or if the
earthquake is centred too close to the coast for the information
provided by the tsunamimeters to be of any use (due to a lack
of time), the concerned populations cannot be protected. On the
other hand, if the authorities responsible for their safety
benefit from similar (simulated) scenarios prior to the
current event, they can take the necessary measures.7(*)
As we will see, this is the solution that Japan has chosen to
limit the impact of tsunamis on its population.
It should be pointed out that the quality of any given
simulation depends in large part on the reliability of the data
used. In particular, an excellent understanding of the concerned
zone's bathymetry and coastal topography is essential for a
correct analysis of the tsunami's propagation and amplification
upon reaching the coast.
b) The role of operational warning systems
Tsunami warning systems are meant to reduce the
vulnerability of populations to this hazard. For them to be
effective, three conditions must be met:
- the warning system is fast, reliable and operational;
- measures for protecting the population are the subject of a preestablished plan;
- the population is informed of the tsunami risk.
Let us now examine each of these conditions in detail.
In order to be operational,
the warning system must be capable of detecting a tsunami early
on, of predicting its propagation, its time of arrival and the
height of its waves along the threatened coasts, and of
transmitting this information to the authorities responsible for
civil protection.
Tsunamis
are detected via measuring instruments. Seismometer networks
allows scientists to locate the epicentre and focus of an
earthquake and to measure its magnitude, in order to determine
if the latter can provoke a tsunami.8(*)
In the event of the answer being yes, the data gathered by the
tsunamimeters and tide gauges allows scientists to confirm the
presence of a tsunami and to refine the information concerning
its amplitude. Therefore, the quick detection of a tsunami
requires not only a sufficient number of measuring devices and
networks, but also networks with advanced means of communication
for the real-time transmission of their data. As for the
early-warning centre, it must not only have access to this
data, it must also be capable of processing and analyzing the
data; this necessitates round-the-clock monitoring, seven days a
week.
- The first type of sensor is linked to an
underwater cable which transmits its data. Such a device
has the advantages of being less expensive to maintain
and having little chance of being damaged. However,
there are two limits to this system: firstly, the
tsunamimeter cannot be installed very far from the coast
(150 km max); secondly, a violent earthquake can snap
the cable. Such cable-linked tsunamimeters are
principally used by the Japanese.
- The second type of sensor is installed on the
seafloor and transmits its data via an acoustical
link to a buoy on the surface which then relays the
data via satellite to the warning centre. The Americans
began to develop this type of device starting in 1997
with their Deep-Ocean Assessment and Reporting of
Tsunamis (DART) buoys, within the framework of their
national programme for limiting the impact of tsunamis.
These sensors are impressively precise, for they are
capable of detecting waves of only one centimetre in
depths of 6,000 metres. In addition, they can be
installed in the middle of the ocean, thereby allowing
for a real forecasting of tsunami events. However, they
are very expensive to install and maintain:
according to the information gathered by your
rapporteur, this type of instrument costs between
€70,000 and €200,000, its installation costs €100,000,
and its obligatory annual visit costs between €50,000
and €70,000; what's more, the device must be replaced
every 5 to 10 years.
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When
a tsunami risk is detected, the information must be quickly
transmitted to the authorities in charge of civil security, so
that they can take the necessary measures.
Taking into account the limited amount of time available
(anywhere between a few minutes and a few hours), the chain of
command and the civil protection plan cannot be improvised.
The authorities chosen to
receive the warning messages must be clearly identified. That is
why in the warning system coordinated by the Intergovernmental
Oceanographic Commission (IOC), each country must designate a
focal point: an organization charged with receiving these
messages. For an effective transmission of this information,
the said organization must provide round-the-clock monitoring,
seven days a week. In the case of an alert, it is responsible
for informing the civil security services.
In addition, emergency plans must be established and tested
beforehand and each person's role and responsibilities
clearly defined. In general, these plans rely on both evacuation
maps based on past tsunamis and inundation maps provided by
numerical simulations.
The
population, therefore, will be encouraged to play an active role
in protecting itself from the impact of a tsunami: depending on
the amplitude of the tsunami, the population will have to
evacuate the beaches and/or certain other low-lying coastal
zones and seek refuge either on higher ground or in a
sufficiently high and strong building. In some cases, the
population will have to wait several hours before being able to
return to the coast. What's more, if it feels an earthquake or
hears a siren, the population must be capable of making the
right decisions. Therefore, an early-warning system is only
effective if the population is informed and well-aware of
the tsunami phenomenon. A policy of prevention is therefore
essential and can be divided into two necessary parts:
- Educating children at school, with both theoretical
instruction (e.g., understanding tsunamis, eyewitness accounts)
and practical instruction (e.g., evacuation exercises);
- Regular communication of the tsunami risk via the
publishing of pamphlets and books, the holding of conferences,
the inauguration of tsunami-specific signals, or organizing
exercises simulating the arrival of a tsunami and the evacuation
of the endangered zone.
Most of the persons interviewed by your interlocuteur pointed
out that this policy of raising the population's awareness of
the tsunami risk often represents the weak link in the
early-warning chain. Not only must it be continually repeated to
remain effective, but the population's receptiveness depends on
its perception of the danger and its cultural and social
behaviour. However, a tsunami is a relatively rare phenomenon
and therefore of little weight in the collective consciousness,
especially among the young. On the other hand, preventive
measures, such as evacuations, have a heavy impact, because they
can paralyze the economy of an entire region during several
hours. Therefore, many warning systems have been designed
in order to both protect the population and avoid false alarms
(deemed catastrophic economically and financially, and which
undermine the credibility of the policy seeking to limit the
impact of tsunamis).
Therefore, it would seem that the policies for managing tsunami
risk cannot be uniform: to be acceptable, suitable and
long-lasting, they must take into account the concerned
population's behaviour, which can be deeply rooted in its
culture, tradition and social practices, thereby determining
which measures would be accepted by the population.
II. A MANAGEMENT OF THE TSUNAMI RISK WHICH VARIES DEPENDING ON THE BASINS
While the tsunami warning system for the Pacific Ocean was
put in place more than forty years ago, it was not until the
Sumatra tsunami of 2004 that the international community
finally decided to provide the other basins with a similar
system.
A. A RISK TAKEN INTO CONSIDERATION FOR THE PAST SEVERAL DECADES IN THE PACIFIC
As stated earlier, the Pacific Ocean is the region the most
often struck by tsunamis. Therefore, it is only logical
that this basin benefited from the very first warning system.
1. The existence of an international tsunami-warning system...
a) History
The creation of an international tsunami warning system in
the Pacific Ocean is the direct result of the increased
frequency of teletsunamis in this zone between 1946 and 1964:
over a period of twenty years, no less than 5 teletsunamis
crossed the Pacific, claiming several thousand victims and
causing considerable damage.
Following the tsunami of 1 April 1946 which originated in the
Aleutian Islands and devastated the island of Hilo, the United
States decided to create the national Tsunami Warning Center at
the site of its geomagnetic observatory in Honolulu.
Following the 4 November 1952 tsunami off the Kamchatka
Peninsula, Japan decided to create its own national warning
centre, which was entrusted to the Japan Meteorological Agency
(JMA). A form of cooperation would eventually emerge between the
Japanese and American warning centres, through the exchange of
seismic data.
On 22 May
1960, a teletsunami devastated Chile and several Pacific
islands. A few months later, the United Nations Educational,
Scientific and Cultural Organization (UNESCO) set up the
Intergovernmental Oceanographic Commission (IOC), charged with
developing global cooperation in oceanic research. Since its
creation, the IOC has established as its mission the prevention
of ocean-related risks, including tsunamis.
The tsunami of 28 March 1964 which originated off the coast
of Alaska accelerated the setting up of a tsunami warning
system for the Pacific: as early as 1965, an international
coordination group for the tsunami warning system in the Pacific
(known as ICG/Pacific) 9(*)1 was created.
The IOC accepted the offer of the United States to expand
the services of its national tsunami warning centre in
Hawaii, which has since been used as the operational warning
centre for all Pacific states.
At the same time, the International Tsunami Information
Centre (ITIC) was created, whose initial mandate was to mitigate
the impact of tsunamis by:
- helping the member states of the ICG/Pacific to develop and improve their tsunami-prevention policies;
- improving the tsunami warning system in the Pacific;
- encouraging tsunami research;
- informing the non-member states of and encouraging them to join the said warning system;
- conducting post-tsunami surveys in order to document and better understand these disasters.
In 1968, the Honolulu observatory officially became the Pacific Tsunami Warning Center (PTWC).
b) The current situation
Today, the Intergovernmental Coordination Group for the
Tsunami Early Warning and Mitigation System in the Pacific
Ocean has 30 member states: Canada, Chile, Ecuador, El Salvador,
the Fiji Islands, France, Guatemala, Indonesia, Japan,
Malaysia, Mexico, New Zealand, Nicaragua, Papua New Guinea,
Peru, the Philippines, South Korea, Russia, Samoa, Singapore,
Thailand, Tonga, the United States and Vietnam.
The first Master Plan was published in 1989. The current
version dates from 1999. It describes the situation of the
warning system at that date, points out the inadequacies and
proposes solutions. It also describes the warning-system
strategy, which has four main parts:
- evaluating the hazard and risks (historical data, on-the-ground research, computer modelling);
- warning (warning centres, monitoring networks, data transmission);
- prevention (education, evacuation, environmental planning);
- research.
Concerning those aspects linked to the evaluation of this
phenomenon and to research, the ICG/Pacific has closely
cooperated since the 1990s with the Tsunami Commission of the
International Union of Geodesy and Geophysics (IUGG), with which
it has organized 6 international workshops centred around
tsunamis. The ICG/Pacific has funded the creation of a database
compiling an inventory of all tsunamis to have occurred in and
outside the Pacific, as well as the creation of a computer
program for modelling tsunamis that is available to all UNESCO
member states.
Three
international warning centres are currently in place: PTWC in
Hawaii, the West Coast and Alaska Tsunami Warning Center
(WC-ATWC) and the Northwest Pacific Tsunami Advisory Center
(NWPTAC), managed by JMA.10(*) Each of these three centres is responsible for a separate zone, as shown in the map below.
Source: ITIC (1) The role of the Pacific Tsunami Warning Center (PTWC)
PTWC, which is administered and financed by the National
Oceanic and Atmospheric Administration (NOAA) of the United
States, serves as the operational centre for the Pacific tsunami
warning system. PTWC has a current staff of twelve, which
provides round-the-clock monitoring, seven days a week. It has
direct, real-time access to more than 150 seismic stations
spread out all over the world, which inform PTWC of all
earthquakes with a magnitude of over 5.5. It also has access to
data from nearly 100 tide gauges and 26 tsunamimeters installed
in the Pacific, which verify if a tsunami has indeed been
generated and estimate its amplitude.
The installation of tsunamimeters since 1997 has greatly
improved the system's effectiveness by significantly reducing
the number of false alerts. Indeed, up until then, evaluating
the tsunami risk essentially depended on data from the seismic
stations: once an earthquake with a magnitude of over 7.5 was
detected, the alert was immediately given. While the tide gauges
near the epicentre were still needed to verify whether a
tsunami had indeed been generated, for these zones, the
information arrived at the same time as the tsunami. It was
therefore necessary to evacuate these areas as a precaution.
However, not all earthquakes, even those of great magnitude,
generate tsunamis. In addition, the number of potentially
concerned countries depends on the formation and propagation of
the tsunami, information which seismic data is currently unable
to provide with sufficient precision. Therefore,
tsunamimeters allow scientists to refine the analysis, follow
the tsunami's propagation and issue (or cancel) a warning up
until the very last minute.
PTWC, ATWC and NWPTAC currently issue three types of
information bulletin. The content of these messages is regularly
revised; indeed, a study is currently under way to revise the
contents so as to make them more precise.
When an earthquake with a magnitude of between 6.5 and 7.5 occurs, an information message
is sent to all civil authorities, specifying the hour and
location of the earthquake and the fact that no tsunami has been
generated.
Example of an information message
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
TSUNAMI BULLETIN NUMBER 001
ISSUED AT 2117Z 16 OCT 2007
THIS BULLETIN APPLIES TO AREAS WITHIN AND BORDERING THE PACIFIC
OCEAN AND ADJACENT SEAS...EXCEPT ALASKA...BRITISH COLUMBIA...
WASHINGTON...OREGON AND CALIFORNIA.
... TSUNAMI INFORMATION BULLETIN ...
THIS BULLETIN IS FOR INFORMATION ONLY.
THIS BULLETIN IS ISSUED AS ADVICE TO GOVERNMENT AGENCIES. ONLY
NATIONAL AND LOCAL GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKE
DECISIONS REGARDING THE OFFICIAL STATE OF ALERT IN THEIR AREA AND
ANY ACTIONS TO BE TAKEN IN RESPONSE.
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS
ORIGIN TIME - 2106Z 16 OCT 2007
COORDINATES - 25.5 SOUTH 179.6 EAST
DEPTH - 411 KM
LOCATION - SOUTH OF FIJI ISLANDS
MAGNITUDE - 6.6
EVALUATION
A DESTRUCTIVE TSUNAMI WAS NOT GENERATED BASED ON EARTHQUAKE AND
HISTORICAL TSUNAMI DATA.
THIS WILL BE THE ONLY BULLETIN ISSUED FOR THIS EVENT UNLESS
ADDITIONAL INFORMATION BECOMES AVAILABLE.
THE WEST COAST/ALASKA TSUNAMI WARNING CENTER WILL ISSUE PRODUCTS
FOR ALASKA...BRITISH COLUMBIA...WASHINGTON...OREGON...CALIFORNIA.
Source: PTWC
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PTWC's reaction time is very short (never more than 20
minutes): in the above example, the earthquake occurred at 9:06
p.m. and the information message was sent at 9:17 p.m.
If an earthquake with a magnitude of between 7.5 and 7.9
occurs, there is a risk of a regional tsunami being generated.
Depending on the supposed direction taken by the tsunami - and,
therefore, the risk run by the concerned countries - PTWC will
issue a warning bulletin (for those countries considered the most at risk) and/or a watch bulletin
(for those countries considered less at risk). The warning is
canceled if the data provided by the tide gauges and/or
tsunamimeters confirms the absence of a tsunami. Otherwise,
supplementary bulletins will be issued with additional
information.
Example of a warning/watch bulletin
WEPA40 PHEB 081908
TSUPAC
TSUNAMI BULLETIN NUMBER 001
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 1908Z 08 MAY 2007
THIS BULLETIN IS FOR AREAS WITHIN AND BORDERING THE PACIFIC
OCEAN AND ADJACENT SEAS...EXCEPT ALASKA...BRITISH COLUMBIA...
WASHINGTON...OREGON AND CALIFORNIA.
... A TSUNAMI WARNING AND WATCH ARE IN EFFECT ...
A TSUNAMI WARNING IS IN EFFECT FOR
JAPAN / RUSSIA / MARCUS IS. / N. MARIANAS
A TSUNAMI WATCH IS IN EFFECT FOR
GUAM / WAKE IS. / TAIWAN / YAP / PHILIPPINES / MARSHALL IS. /
CHUUK / POHNPEI / BELAU / MIDWAY IS. / KOSRAE / INDONESIA /
PAPUA NEW GUINEA / NAURU / KIRIBATI / JOHNSTON IS. / HAWAII
FOR ALL OTHER AREAS COVERED BY THIS BULLETIN, IT IS FOR
INFORMATION ONLY AT THIS TIME.
THIS BULLETIN IS ISSUED AS ADVICE. ONLY NATIONAL OR LOCAL
GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKE DECISIONS
REGARDING THE OFFICIAL STATUS IN EACH AREA AND ANY ACTIONS TO
BE TAKEN IN RESPONSE.
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS
ORIGIN TIME - 1848Z 08 MAY 2007
COORDINATES - 38.2 NORTH 143.1 EAST
DEPTH - 47 KM
LOCATION - OFF EAST COAST OF HONSHU JAPAN
MAGNITUDE - 8.2
EVALUATION
IT IS NOT KNOWN THAT A TSUNAMI WAS GENERATED. THIS WARNING IS
BASED ONLY ON THE EARTHQUAKE EVALUATION. AN EARTHQUAKE OF THIS
SIZE HAS THE POTENTIAL TO GENERATE A DESTRUCTIVE TSUNAMI THAT CAN
STRIKE COASTLINES NEAR THE EPICENTER WITHIN MINUTES AND MORE
DISTANT COASTLINES WITHIN HOURS. AUTHORITIES SHOULD TAKE
APPROPRIATE ACTION IN RESPONSE TO THIS POSSIBILITY. THIS CENTER
WILL MONITOR SEA LEVEL DATA FROM GAUGES NEAR THE EARTHQUAKE TO
DETERMINE IF A TSUNAMI WAS GENERATED AND ESTIMATE THE SEVERITY OF
THE THREAT.
ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES. ACTUAL ARRIVAL TIMES
MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE LARGEST. THE TIME
BETWEEN SUCCESSIVE TSUNAMI WAVES CAN BE FIVE MINUTES TO ONE HOUR.
LOCATION COORDINATES ARRIVAL TIME
-------------------------------- ------------ ------------
JAPAN HACHINOHE 40.5N 142.0E 1932Z 08 MAY
KUSHIRO 42.5N 144.5E 1933Z 08 MAY
KATSUURA 35.1N 140.3E 1934Z 08 MAY
SHIMIZU 32.5N 133.0E 2047Z 08 MAY
OKINAWA 26.2N 127.8E 2148Z 08 MAY
RUSSIA URUP IS 46.1N 150.5E 2016Z 08 MAY
PETROPAVLOVSK K 53.2N 159.6E 2123Z 08 MAY
SEVERO KURILSK 50.8N 156.1E 2130Z 08 MAY
UST KAMCHATSK 56.1N 162.6E 2148Z 08 MAY
MEDNNY IS 54.7N 167.4E 2150Z 08 MAY
MARCUS IS. MARCUS IS. 24.3N 154.0E 2055Z 08 MAY
N. MARIANAS SAIPAN 15.3N 145.8E 2159Z 08 MAY
GUAM GUAM 13.4N 144.7E 2216Z 08 MAY
WAKE IS. WAKE IS. 19.3N 166.6E 2223Z 08 MAY
TAIWAN HUALIEN 24.0N 122.0E 2234Z 08 MAY
YAP YAP IS. 9.5N 138.1E 2252Z 08 MAY
PHILIPPINES PALANAN 17.1N 122.6E 2253Z 08 MAY
LEGASPI 13.5N 124.0E 2312Z 08 MAY
DAVAO 6.5N 126.0E 2339Z 08 MAY
MARSHALL IS. ENIWETOK 11.4N 162.3E 2256Z 08 MAY
KWAJALEIN 8.7N 167.7E 2341Z 08 MAY
MAJURO 7.1N 171.4E 0010Z 09 MAY
CHUUK CHUUK IS. 7.4N 151.8E 2258Z 08 MAY
POHNPEI POHNPEI IS. 7.0N 158.2E 2312Z 08 MAY
BELAU MALAKAL 7.3N 134.5E 2316Z 08 MAY
MIDWAY IS. MIDWAY IS. 28.2N 177.4W 2325Z 08 MAY
KOSRAE KOSRAE IS. 5.5N 163.0E 2340Z 08 MAY
INDONESIA GEME 4.6N 126.8E 2346Z 08 MAY
BEREBERE 2.5N 129.0E 2356Z 08 MAY
PATANI 0.4N 128.8E 0022Z 09 MAY
WARSA 0.6S 135.8E 0022Z 09 MAY
MANOKWARI 1.0S 134.5E 0032Z 09 MAY
JAYAPURA 2.4S 140.8E 0042Z 09 MAY
SORONG 0.8S 131.1E 0045Z 09 MAY
PAPUA NEW GUINE KAVIENG 2.5S 150.7E 0025Z 09 MAY
MANUS IS. 2.0S 147.5E 0029Z 09 MAY
VANIMO 2.6S 141.3E 0040Z 09 MAY
RABAUL 4.2S 152.3E 0044Z 09 MAY
WEWAK 3.5S 144.0E 0053Z 09 MAY
AMUN 6.0S 154.7E 0109Z 09 MAY
KIETA 6.1S 155.6E 0112Z 09 MAY
MADANG 5.2S 145.8E 0112Z 09 MAY
LAE 6.8S 147.0E 0150Z 09 MAY
PORT MORESBY 9.3S 146.9E 0308Z 09 MAY
NAURU NAURU 0.5S 166.9E 0043Z 09 MAY
KIRIBATI TARAWA IS. 1.5N 173.0E 0056Z 09 MAY
KANTON IS. 2.8S 171.7W 0224Z 09 MAY
CHRISTMAS IS. 2.0N 157.5W 0337Z 09 MAY
MALDEN IS. 3.9S 154.9W 0412Z 09 MAY
FLINT IS. 11.4S 151.8W 0506Z 09 MAY
JOHNSTON IS. JOHNSTON IS. 16.7N 169.5W 0059Z 09 MAY
HAWAII NAWILIWILI 22.0N 159.4W 0153Z 09 MAY
HONOLULU 21.3N 157.9W 0207Z 09 MAY
HILO 20.0N 155.0W 0228Z 09 MAY
BULLETINS WILL BE ISSUED HOURLY OR SOONER IF CONDITIONS WARRANT.
THE TSUNAMI WARNING AND WATCH WILL REMAIN IN EFFECT UNTIL
FURTHER NOTICE.
THE JAPAN METEOROLOGICAL AGENCY MAY ALSO ISSUE TSUNAMI MESSAGES
FOR THIS EVENT TO COUNTRIES IN THE NORTHWEST PACIFIC AND SOUTH
CHINA SEA REGION. IN CASE OF CONFLICTING INFORMATION... THE
MORE CONSERVATIVE INFORMATION SHOULD BE USED FOR SAFETY.
THE WEST COAST/ALASKA TSUNAMI WARNING CENTER WILL ISSUE BULLETINS
FOR ALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.
Source: PTWC
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An earthquake with a magnitude of over 7.9 risks provoking
a tsunami that will cross the entire Pacific. For the
Pacific zone, PTWC sends its bulletins to more than 100
different sites.
At
this stage, it became clear that the system could only be
effective if it benefited from excellent international
cooperation. While it is true that the United States
has its own seismic stations and tide gauge stations, as well as
accounting for most of the tsunamimeters, the system also
collects data from the measuring devices of other countries.
Therefore, the rapid, free exchange of all of the data is
essential. PTWC must therefore work in close collaboration with
other international, national and regional warning centres,
which make their data available to PTWC. In particular, the
WC-ATWC11(*) is meant to be able to stand in for PTWC in the case of technical difficulties.
Furthermore, improving the system is dependent on the
installations of each subzone, meaning a sufficient number of
tide gauges and tsunamimeters.
For instance, the following map illustrates the work
remaining to be done in the South Pacific, which appears
underequipped, both off the coast of Chile and around the Tonga
Archipelago.
Source: International Tsunami Information Centre
(2) The actions of the International Tsunami Information Centre (ITIC)
The International Tsunami Information Centre (ITIC)
continues to play a fundamental role in the tsunami warning
system: as secretary of the intergovernmental coordination group
for the tsunami warning system in the Pacific, it coordinates
its members' preventive measures and recommends necessary
improvements with regard to data collection and dissemination.
It has organized 3 ICG/Pacific meetings since 2004, as well as
the first warning exercise for the entire Pacific zone, which
was held on 16 and 17 May 2006 and for which it later published
the assessment.
It also helps the member states set up national and regional tsunami warning systems.
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The ITIC also publishes a newsletter and educational pamphlets, including The Great Waves and The Tsunami Glossary
(both edited and published in France). It carries out
public-awareness campaigns and has even developed, in
cooperation with Chile, educational programmes for children
which have been integrated into this country's school
programmes. In addition, every year it organizes in Hawaii or
some other location training courses for those persons
responsible for managing its members' national warning centres.
Finally, its writ has been
extended since the Sumatra tsunami of 2004, and it is now in
charge of helping countries in the other basins to develop their
own warning systems. The ITIC is particularly active in the
Indian Ocean, where it plays an advisory role with regard to
data communication, the interoperability of seismic and tide
gauge networks and the methods used for forecasting
tsunamis. It also organizes on-site assessments12(*), training courses, symposiums and work group meetings.
Overall, the warning system in the Pacific works well and
represents the most sophisticated and operational system.
That is why PTWC has been put in charge of issuing warnings for
the Indian Ocean zone, until this basin has its own warning
system up and running.
Likewise, in the interim, PTWC covers the Caribbean zone and
issues warnings to those countries surrounding the South China
Sea (China, Macao, Hong Kong, Taiwan, the Philippines, Malaysia,
Brunei, Indonesia, Singapore, Thailand, Cambodia and Vietnam).13(*)
Nevertheless, certain improvements could be made to render
the system more effective in the Pacific. Several regional
warning centres should be set up, so as to better take into
account the risks posed by regional tsunamis. The concerned
regions are the Southwest Pacific, Central America, South
America and the China Seas.
What's more, the absence of any devastating trans-Pacific
tsunamis for over 40 years could make it difficult to fund the
system in the long term. As has already been pointed out,
maintaining the DART buoys is particularly expensive and the
United States is the main contributor to the warning system. The
decisions made by the United States Congress are therefore
closely monitored by all the other countries of the
intergovernmental coordination group.
During the last meetings of the ICG/Pacific, two priorities were established:
- improve the warning messages, so that they include
information on the expected magnitude of the tsunamis along the
Pacific coasts;
- revise the warning system, to make it operational in the event of local tsunamis.
2. ... that relies on effective national systems
The three national systems here presented constitute the
most successful warning systems to date. While they may not be
perfect, they endeavour to meet the three preconditions for
setting up an effective warning system: 1) an operational
warning centre, 2) a pre-defined, emergency action plan that has
been pre-tested on the ground, and 3) a population informed and
made aware of the threat.
a) The American model
(1) Two warning centres
The Hawaiian centre has already been discussed above;
however, it is necessary to emphasize the fact that this centre
has retained its original warning mission for the United States.
Indeed, the US National Tsunami Warning Center issues tsunami
warning bulletins for Hawaii, Guam, American Samoa, Wake Island,
Johnston Island, the Northern Mariana Islands and all other
American interests in the Pacific not covered by the Alaskan
warning centre.
What's
more, as the regional tsunami warning centre for Hawaii, PTWC
rapidly issues warning bulletins in the event of a local tsunami
generated in the Hawaiian waters.
According to the information gathered by your rapporteur,
there are 70 seismic stations located in Hawaii. PTWC requires
10 seconds to detect an earthquake, 15 seconds more for its
localization, and 1.5 minute to determine its magnitude.
However, considering the very short time lapse between the
generation of a tsunami and its arrival on the coasts (10
minutes for the local tsunami of 29 November 1975), teaching the
concerned population the right reflexes remains the most
effective protective measure: when someone along the coast feels
the ground shake, he/she must immediately seek higher ground,
without waiting for an official warning.
In addition to PTWC, the United States created a second
warning centre for Alaska in 1967, following the teletsunami of
27 March 1964 which originated in this region.14(*)
In 1982, the geographical zone for which the centre issues
its warning bulletins was extended to the states of
California, Oregon, Washington and British Colombia, in the
event of a tsunami-generating earthquake occurring in their
coastal zones.
In 1996, the
Alaskan centre once again had its mission extended, for it is
now in charge of warning the four previously mentioned states in
the event of a tsunami originating anywhere in the Pacific.
Following the devastating
Sumatra tsunami of 26 December 2004, the WC/ATWC could also
issue tsunami warnings to the Atlantic coast of the United
States, as well as the Gulf of Mexico region, Puerto Rico, the
Virgin Islands and the Atlantic coast of Canada.
Therefore, the United States has two tsunami warning
centres which ensure the protection of its coasts and can
replace one another if need be (should one centre encounter
technical difficulties which prevent it from functioning
correctly, or should several tsunamis originate in different
areas at the same time).
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(2) A national plan to limit the impact of tsunamis
While the risks run by Hawaii in the event of a tsunami
have long been known, it is only rather recently that the
states of Washington, Oregon and California are also recognized
as being vulnerable.
An earthquake in the Cascades subduction zone15(*)
in April 1992, which provoked a tsunami in northern California,
underlined the shortcomings of the warning system. On 4 October
1994, a Pacific-wide tsunami warning was issued following a
strong, tsunami-generating earthquake in the Kuril Islands. In
the United States, this event provoked enormous confusion
between the various emergency services, resulting in the
costly evacuation of Hawaii which drew sharp criticism when the
warning turned out to be false.
To remedy this situation, Congress decided to launch in
1995 the National Tsunami Hazard Mitigation Program (NTHMP)
under the direction of the NOAA and covering both the coastal
states and America's island protectorates.
This programme relies on three main lines:
- tsunami evaluation: a better understanding of past
tsunamis will produce more refined inundation maps based on
long-term tsunami forecasting;
- the quality of the warning system, through the improved
collection and processing of seismic data, the deployment of a
network of tsunami-detection buoys, and a better transmission of
the warning information to the competent authorities;
- preventive measures, via the early elaboration of
prevention and evacuation plans, as well as the development of
educational materials to help raise public awareness.
Taking into account the subsidiarity rules linked to
federalism, a close partnership has developed between the
federal, state and local authorities.
In addition, the NOAA launched a programme entitled
"TsunamiReady", which encourages the at-risk communities and
states to adopt those measures necessary to effectively mitigate
the effects of a tsunami.
Based on the principle of voluntary participation, this
programme sets the criteria which must be respected in order to
earn this label, including:
- establishing a 24-hour warning point and emergency operations centre;
- have more than one way to receive tsunami warnings and alert the public;
- increase public awareness through the distribution of information and community education;
- develop a formal tsunami plan, which includes holding periodic emergency exercises.
To this day, 47 sites16(*)
(cities, counties, beaches, harbours) in 10 different states
have earned this label. Hawaii is the only state considered
"tsunami ready".
In
addition, following the devastating Sumatra tsunami, the
President of the United States proposed a $37.5 million package
to improve the national warning systems. In May 2005, the
Emergency Supplemental Appropriations Act was passed, which
granted an additional $17.24 million to the NOAA in order to
extend and improve its tsunami-detection capabilities, to make
the warning centres more effective, to produce inundation maps
and to extend the TsunamiReady programme to all coastal states. A
new law was passed in August 2006 to extend the NOAA's budget
from $25 million in 2008 to $29 million in 2012.
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(3) A permanent prevention policy
The state of Hawaii is certainly the most advanced with
regard to its tsunami-mitigation policy. During his visit to
Hawaii, your rapporteur was able to observe the mobilization of
various stakeholders involved in every level of civil protection
in the case of a tsunami warning being issued. On the Big
Island of Hawaii, the city of Hilo, which was particularly
affected by the tsunamis of 1946, 1960 and 1975, has provided
itself with a very complete warning system under the impetus of
its mayor.
First of all,
the warning plans are decided upon in advance: the evacuation
maps have already been prepared and distributed to all public
services. They are also included in the telephone directory.
There is only one commander (the mayor) and each official's
responsibilities are clearly defined.
Secondly, to ensure that all officials give out the same
information, the messages to be emitted are prepared from
preprinted, fill-in-the-blank style texts (officials fill in the
date, hour and location of the earthquake, the expected date of
the tsunami's arrival, and the deadline for evacuating at-risk
zones).
For a rapid
dissemination of the information, an agreement was passed with
the radio stations, by which they agree to interrupt their
programmes in order to read the warning messages transmitted by
the civil protection officials.
In addition, a network of sirens has been installed, in
order to alert the population in the event of a tsunami warning.
Also, under the authority
of the mayor, the lessons learned from past tsunamis have been
incorporated into the city's urban planning: following the
tsunami of 1946, a large section of the inundated zone was
converted into a park. Following the tsunami of 1960, the buffer
zone was enlarged and the debris were used to build a natural
barrier separating the coastline from the interior. In addition,
the building of hospitals, schools and retirement homes was
prohibited in those zones prone to inundation, while those
buildings located on the seashore are subject to strict safety
standards (the buildings must be capable of resisting a tsunami,
no ground-floor bedrooms).
Finally, in memory of the devastating tsunami of 1 April 1946,
the month of April is used to raise public awareness of the
tsunami risk. A training exercise simulating the arrival of a
tsunami is carried out throughout the entire state of Hawaii,
with the participation of PTWC, state officials, the departments
of education and transportation, the harbour authorities and
hotel associations. Evacuation drills are also carried out in
certain schools located in at-risk zones.
Everyone your rapporteur spoke with insisted on the need to
form close, long-lasting ties with the media, in order to
both avoid the diffusion of incomplete or erroneous information
and to raise public awareness of this phenomenon and how to
behave in the event of a tsunami.
b) The Japanese model
(1) A system especially well-suited to local tsunamis
With an average of 2,000 earthquakes per year (almost 5 per
day) liable to be felt by the population, Japan is the most
earthquake-prone country in the world. Many of these
earthquakes occur at sea, which explains why Japan is also the
most tsunami-prone country in the world. The following table
lists the most destructive tsunamis since the beginning of the
20th century.
List of Japanese tsunamis
since the beginning of the 20th century
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Source: Japan Meteorological Agency
In addition, while Japan is concerned by transpacific
teletsunamis, it is above all affected by local tsunamis that
are often devastating. Therefore, this country has set up a
warning system capable of alerting the population in only a few
minutes.
The Japan
Meteorological Agency (JMA), under the authority of the Ministry
of Infrastructure and Transportation, constitutes the country's
nation-wide, multi-risk warning centre. JMA collects data on
natural phenomena and issues warnings to the authorities and the
public should the need arise.
Insofar as local tsunamis leave little time to act, the
Japanese warning system favours rapidly emitting a warning
message, even if it should later turn out to be false. Within
three minutes following the detection of a tsunami, JMA will
issue a message with the estimated time of the tsunami's
arrival, the concerned coasts and the estimated height of the
wave(s).
There are two
types of local tsunami forecast messages: warning messages (the
wave must be higher than 1 metre) and information messages (when
the wave is between 50 cm and 1 metre in height).
In addition, there exist two categories of warning
messages: messages for tsunamis with estimated waves of up to
two metres and messages for major tsunamis with waves of three
metres or higher.
Tsunami forecast and information
Tsunami forecast
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Created within 3 to 5 minutes following the earthquake.
Distributed according to the height of the tsunami.
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Information on the estimated time of arrival and
the height of the tsunami for each coastal region.
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Information on the time of arrival of the high tide
and the tsunami on the coasts.
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Information on the actual time of arrival and height of the tsunami.
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Source: Japan Meteorological Agency
In addition, JMA has divided the Japanese coast into 66
regions, which receive warning messages and information when
they are concerned by a tsunami risk.
Division of the Japanese coast into 66 regions
Source: Japan Meteorological Agency
JMA benefits from a very dense network of seismic stations
(182) and tide gauges (80), whose data is supplemented by
that provided by the measuring devices of the local governments,
the NIED17(*)
and the coast guard. This information is transmitted via
satellite in real time to JMA, where it is processed by computer
in order to determine as quickly as possible the earthquake's
hypocentre and magnitude and if a tsunami has indeed been
generated.
However, the
extremely short amount of time (3 minutes) allowed JMA to issue a
warning message does not, in fact, allow it to verify if the
detected earthquake has actually provoked a tsunami (the network
of stations for measuring sea level is not sufficiently dense
to detect a tsunami in under 3 minutes). In reality, JMA relies
on tsunami simulations based on 100,000 tsunami-generating
earthquakes, comparing the detected earthquake to the
simulation of the earthquake with the most similar
characteristics. At the same time, once the information on the
detected earthquake has been collected, a new simulation is
carried out to refine the information given on the potential
tsunami.
The warning messages are very widely distributed.
Firstly, they are sent to local authorities and disaster-control bodies.
Secondly, JMA has passed a cooperative agreement with the
public television network NHK for the broadcasting of warning
messages. NHK manages 10 TV channels and 3 radio stations,
which all issue warnings in the event of a tsunami. When an
alert is given, the TV and radio programmes are interrupted and a
message is broadcast, accompanied with a map of Japan with the
at-risk zones coloured yellow, orange or red, depending on the
amplitude of the forecast tsunami.
During the Kobe earthquake of 17 January 1995, serious
systemic failures were observed, due, in particular, to an
insufficient distribution of earthquake information. For this
reason, the tsunami warning system now favours diverse channels
for the transmission of information to persons capable of making
decisions. For example, in the Wakayama Prefecture, at least
three bodies now receive JMA messages and are liable to activate
the sirens to alert the public to the danger.
(2) A well-prepared population
Local tsunamis necessitate very short reaction times. In
at-risk zones, the local authorities have set up evacuation
plans detailing the routes to take, the buildings that can serve
as a refuge and the zones to reach in order to be safe.
Particular attention has been paid to signalling and several
types of signs have been created:
- signs indicating the direction and distance to the safety zones;
- warning signs for those zones prone to inundation in the event of a tsunami;
- signs indicating safety zones (out of reach of the tsunami) and "refuge" buildings.
These signs rely almost entirely on drawings, allowing them to be understood by everyone.
Sirens have also been installed along the coasts, with a
range of 1 to 2 kilometres, in order to warn persons on the
beaches and along the seashore.
In addition, numerous measures have been taken to inform
and raise the awareness of the public. For example, the
department responsible for dealing with catastrophes and fires,
placed under the authority of the Ministry of Internal Affairs
and Communications, has developed an informative CD for
shoreline residents. This CD explains how tsunamis are generated
and spread, and then describes what to do should the sirens be
sounded and/or a strong earthquake be felt.
The inhabitants of certain districts are involved in the
process of designing the evacuation plans. The objective is to
inform the public of the damages caused by past tsunamis,
convince it of the usefulness of such plans, and profit from
their knowledge of the area in order to choose the best
evacuation routes.
Training
exercises are also carried out, to test the chosen escape
routes and solve any observed failures or shortcomings. Your
rapporteur learned of a group of residents that worked during
two years to construct an escape route (using railway tracks)
providing rapid access to a zone located 10 metres above sea
level.
For all that, Japan
must still deal with public apathy in the face of such a rare
phenomenon. Several persons pointed out to your rapporteur the
worrying fact that during the last warnings of November 2006 and
13 January 2007, most residents remained at home, despite
orders to evacuate. One possible explanation, other than a
changing Japanese society, resides in the fact that the issuance
of numerous false warnings has damaged the system's
credibility.
(3) Considerable means dedicated to constructing protective structures and improving the warning system
Japan is the only country building more and more structures to protect against tsunamis.18(*)
The municipality of Tokyo, which is responsible for the
security of the islands off its coast, has sought to reduce the
vulnerability of certain coasts by installing tetrapods and
artificial reefs.
According
to the information gathered by your rapporteur, more than
15,000 km of dikes have been built along the Japanese coast.
For those areas without a
nearby building offering refuge and whose relief does not allow
residents to rapidly access a zone several metres above sea
level, the Japanese have constructed steel platforms with
stairways. These platforms are earthquake-resistant and capable
of resisting tsunami waves. They can shelter between 70 and 100
persons and are sometimes equipped with a siren.
Likewise, concrete walls or dikes are sometimes built in
harbours threatened by tsunamis. These walls, whose height can
be adjusted according to the estimated amplitude of the
tsunami, are meant to "break" the waves and limit inundation.
In addition, Japan continues to invest heavily in the improvement of its warning system. JAMSTEC19(*) has launched a programme entitled DONET20(*),
whose objective is to equip the Tonankai zone with a
network of 20 seismometers linked by cable that also act as
pressure sensors, in order to more rapidly detect earthquakes
and tsunamis originating in this zone. It should be pointed out
that the study of past earthquakes has shown that the zone
between the Bay of Suroga and the island of Shikoku produces an
earthquake with a magnitude of 8 or greater every 100 to 150
years, at three different locations: in the regions of Tokai,
Tonankai and Nankai.
The strong earthquakes liable to touch
the regions of Tokai, Tonankai and Nankai
Source: Japan Meteorological Agency
In addition, in this same zone, two strong earthquakes have
already occurred more or less instantaneously or were
separated by only one or two days. Such an event would produce
enormous damage. That is why this zone is under high monitoring.
Finally, Japan is greatly
involved in the overall improvement of the world's tsunami
warning systems, thanks to its very active policy of
cooperation, in particular with the other Asian and Pacific
countries.
Since 1960, the IISEE21(*)
has organized a one-year training course for a dozen engineers
from developing countries on seismology and earthquake
prevention and mitigation techniques. Up until 1972, Japan and
UNESCO codirected this training programme. However, in 1973,
Japan's JICA22(*)
became the sole director of the programme and in 2005
transformed it into a Masters in natural disaster prevention. In
2006, a tsunami module was introduced; when your rapporteur
visited Japan in January 2007, this module was being followed by
5 students, or half of the programme's participants.
In addition, NIED and JICA have begun to set up a seismic
network in Indonesia (the JISNET project): 23 broadband
seismic stations have already been installed.
In the southwest Pacific, JICA has financed a programme to
upgrade the seismic networks of the Fiji and Tonga islands:
the South Pacific broadband seismic NETwork (SPANET). 6
broadband seismic stations have already been installed.
c) The French model in Polynesia
(1) CEA at the heart of the Polynesian warning system
The creation of a national tsunami warning centre in
Polynesia is directly linked to France's nuclear activities in
the Pacific.
Set up by CEA
("Atomic Energy Commissariat") in the beginning of the 1960s,
France's geophysical laboratory (or "LDG") in Tahiti has, since
1964, been responsible for providing information on those
tsunamis liable to affect the coasts of French Polynesia. For
this reason, it set up the Polynesian seismic network and has
developed ever more advanced methods for evaluating the
tsunami-generating potential of earthquakes.
Today, the activities of the Pamatai geophysical laboratory can be divided into three categories:
Firstly, within the framework of the Comprehensive
Nuclear-Test-Ban Treaty, LDG/Pamatai is part of the
international nuclear-explosion monitoring system.
Secondly, LDG/Pamatai's seismic network for Polynesia is
responsible for the round-the-clock monitoring of French
Polynesia's seismicity; this includes earthquakes, underwater
volcanoes, landslides and storm surges. Within this framework,
since 1962, LDG/Pamatai has made use of 9 seismic stations
located in Tahiti, Rangiroa, Tubuai and Rikitea.
Finally, LDG/Pamatai manages the Polynesian tsunami
prevention centre, which ensures 24-hour tsunami monitoring for
the Pacific zone, in partnership with PTWC.
The Comprehensive Nuclear-Test-Ban Treaty
This treaty, adopted on 10 September 1996 and
signed by 71 countries (including the 5 official
nuclear powers) on 24 September 1996, forbids nuclear
testing. It complements the treaty of 5 November 1963,
which prohibs underwater, outer-space and atmospheric
nuclear testing, by extending the ban to underground
testing.
This treaty set up an international monitoring
system for the air, water and oceans via stations
scattered throughout the world.
Stations for detecting radionuclides (airborne
radioactive elements) and infrasonic vibrations are
used for the atmosphere.
Seismometers are used to detect seismic waves
generated by earthquakes or underground explosions.
These sensors can also be used to monitor the oceans,
by detecting and identifying propagating hydroacoustic T
waves.
DASE23(*),
which oversees LDG/Pamatai, is responsible for France's
contribution to the international monitoring system
(IMS), with regard to the various technologies
(seismic, radionuclide, infrasonic-vibration and
hydroacoustic) used.
The Polynesian geophysical network includes IMS
stations whose data is sent to DASE and the
international data centre in Vienna.
Due to its central location in the Pacific, the
seismic station in Tahiti is a key site for seismic
and hydroacoustic monitoring. The
radionuclide-analysis station is located at the Pamatai
site. Two infrasonic-vibration stations are located in
Taravao (on the Tahitian peninsula) and the Marquesas
Islands.
Source: DASE
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When LDG/Pamatai detects an earthquake with an underwater
focus less than 60 km deep and a magnitude of 7 or greater,
it informs the State Authority and the civil protection service.
It should here be pointed
out that LDG/Pamatai has developed a highly effective system for
the automatic, real-time detection and localization of
tsunami-generating earthquakes called TREMORS®24(*) (Tsunami Risk Evaluation through seismic MOment from a Realtime System).
The energy released during an earthquake constitutes its
"magnitude". The greater the magnitude, the more energy
released by the earthquake. It consists of a logarithmic scale;
in other words, an increase of 1 step corresponds to a 30 fold
increase in the amount of energy released. While the Richter
Scale (Ms) is the best known magnitude scale, it has the
disadvantage of becoming saturated in the case of a strong
earthquake: the magnitude reaches a ceiling that it has
difficulty passing, even while the amount of released energy
continues to increase. To solve this saturation problem, the
moment magnitude scale (Mw) was developed in the 1980s. This
scale is in line with the Ms scale and acts as its extension for
earthquakes of greater magnitude, so as to avoid the saturation
effect. For example, the earthquake of 22 May 1960 in Chile had
a magnitude of 8.4 on the Richter Scale and a magnitude of
9.5 on the Moment Scale. Therefore, it was in fact 30 times
greater than the instruments indicated at the time.
Using the Richter Scale to measure the magnitude of strong
earthquakes can result in greatly underestimated tsunami
forecasts. That is why a precise measurement of magnitude is
essential. However, according to the information obtained by
your rapporteur, the Moment Scale requires numerous seismic
stations and considerable calculation means.
To overcome these difficulties, LDG/Pamatai has introduced
a new magnitude scale, the Mm (Mantle Scale), which avoids
the saturation effect plaguing the Richter Scale and requires
only one seismic station. Beyond a certain magnitude threshold
(currently set at 7), a warning is issued by GMS to the
geophysicist on duty.
Source: CEA/DASE/LDG/Pamatai
In addition, LDG/Pamatai uses four tide gauges installed in
Papeete (1), the Gambier Islands (1) and the Marquesas
Islands (2). Only one of these stations was financed by France
via a FIDES project ("Investment Fund for Socio-Economic
Development"). It also receives data from some twenty tide
gauges installed, for the most part, in the South Pacific on
islands located between the tsunami-generating zones and French
Polynesia.
These activities
are complemented by studies and simulations meant to better
evaluate the tsunami hazard in Polynesia (see above).
It is not surprising that CEA represents France at the
ICG/Pacific, for which it has assumed first the vice-presidency,
then the presidency, and that it was actively involved in
establishing the specialized tsunami emergency plan ("PSS") for
French Polynesia25(*).
(2) A warning system based on a deep understanding of tsunamis
As has already been pointed out, the effectiveness of any
warning system depends on a good prior understanding of the
hazard. That is why several studies were entrusted to CEA, in
order to produce a tsunami map.
The
analysis of earthquakes in the Pacific zone between the years
1837 and 2005 suggests that the Polynesian coasts were touched
by at least 15 tsunamis during this period (11 of which caused
damage and 2 of which were deadly).
The tsunami risk in French Polynesia
Source: CEA/DASE
Only exceptionally strong subduction earthquakes (an Mm
magnitude greater than 9) threaten to generate a transpacific
teletsunami that could endanger all of Polynesia. The main
subduction zones capable of producing such an earthquake are
those of the South American coast (Chile, Peru), the Aleutian
island arc and the Pacific Northwest (the Kuril island arc,
Japan, Kamchatka). However, with regard to the last zone, the
risk would seem to be less great, insofar as Polynesia lies
outside the area of maximum effect for tsunamis originating in
this zone.
Therefore, we can identify three seismic zones liable to generate the most devastating tsunamis:
- The South American coastal zone (Chili, Peru). It should
be pointed out that a seismic gap exists north of Chile:
sometime in the next 20 to 30 years, a magnitude 9 earthquake is
expected to occur in this zone, generating a particularly
destructive tsunami in the Marquesas Islands, with simulations
predicting a wave 11 metres high and inland penetrations of up
to 1 km on the island of Hiva Oa;
- The Aleutian island arc;
- The Tonga-Kermadec zone to the west. The seismic history
of this region is not well known, but computer simulations
suggest that a devastating tsunami originating in the Tonga
Archipelago could touch French Polynesia. In addition, a seismic
gap has been identified in the Kermadec Islands, suggesting
that a strong earthquake is to be expected in this zone.
Moreover, on-site observations and computer simulations
reveal a strong variation of the tsunami hazard depending on
the islands, as shown in the following map prepared by CEA:
French Polynesia tsunami exposure levels
Source: CEA/DASE
The Marquesas Islands appear particularly vulnerable to
tsunamis, because they can be affected by major tsunamis more
than 4 times per century. What's more, tsunamis generated by
earthquakes off the South American coast are significantly
amplified in this area. For example, during the magnitude-7.3
earthquake off the coast of Peru on 21 February 1996, a tsunami
of 2-3 metres was observed in the Marquesas Islands, compared to
only 10 cm in Papeete. This amplification is linked to the
local bathymetry: these islands have gently sloping underwater
reliefs and are not protected by coral reefs.
In the Austral Islands, the island of Rurutu is also liable
to be touched twice per century by tsunamis. The other
islands are protected by the barrier reef, thereby mitigating
the effects of tsunamis.
As
for Tahiti, this island is relatively protected by its coral
reef, except for its north and northeastern coasts.
The map indicating those zones likely to generate the most
devastating tsunamis for French Polynesia and the tsunami
exposure level map have both served as references in setting up
the warning system.
As for
the American and Japanese systems, the warnings are divided into
different risk levels. Three colour codes have been defined,
according to the seriousness of the threat.
The level 2 warning (yellow) is set off by earthquakes with
an Mm magnitude of greater than 8 and when the tsunami's
estimated time of arrival on the Polynesian coasts is announced
less than 9 hours in advance. In this case, LDG/Pamatai notifies
the civil protection service and the High Commissioner.
The level 3 warning (orange) is set off by earthquakes with
an Mm magnitude of between 8.7 and 9 and when the tsunami's
estimated time of arrival on the Polynesian coasts is announced
less than 6 hours in advance. In this case, the threat of a
tsunami is certain and all local authorities are informed.
Finally, the level 4 alert (red)
is set off either by an earthquake with an Mm magnitude of
above 9, or when the tsunami's expected time of arrival on the
Polynesian coasts is announced less than 3 hours in advance.
Concretely, this means that an earthquake with a magnitude of
greater than 8 in the Tonga Islands zone would automatically set
off a maximum warning. The general alert is therefore given, in
order to evacuate the coastal population, to evacuate the
boats from the harbours and to evacuate the airport. Indeed, a
study of the area has demonstrated that Papeete's Faa Airport
would be inundated and rendered useless.
Warning levels
Place of Origin
|
Tonga
|
South America
|
All zones except Tonga
| ||
Magnitude
|
Mm >8
(Mw >7.9)
|
Mm >7
(Mw >7.2)
|
8 < Mm < 8.7
(7.9 < Mw < 8.3)
|
8.7 < Mm < 9 (8.3 < Mw < 8.7)
|
Mm >9
(Mw>8.7)
|
Archipelago
|
French Polynesia
|
Marquesas Islands
|
French Polynesia
| ||
9 hrs
|
2
|
2
|
2
|
3
| |
6 hrs
|
2
|
2
|
3
|
4
| |
3 hrs
|
4
|
4
|
4
|
4
|
4
|
Cancelation
|
1
|
1
|
1
|
1
|
1
|
Level 1
|
Normal situation
| ||||
Level 2
|
Alert authorities
|
High authorities (state and territorial)
| |||
Level 3
|
Alert local authorities
|
Districts and local authorities (the mayor)
| |||
Level 4
|
Global warning
|
Evacuation of the population
| |||
Considering the Marquesas Islands' great exposure to
tsunamis, a warning level of 2 is set off by an earthquake with a
magnitude of greater than 7 occurring off the South American
coast.
(3) A warning system best suited to the characteristics of French Polynesia
As has been pointed out several times, a warning system is
only effective if it affects the population and if the
population reacts accordingly. However, the distinctive
characteristics of French Polynesia make setting up a warning
system difficult.
Firstly,
this territory has a surface area of 4,200 km² scattered over
5 million km² of ocean, with 256,000 inhabitants divided between
dozens of islands. While it is true that 80% of the population
is concentrated on Tahiti and Moorea, 8,000 persons people the 5
Marquesas Islands and 5,000 inhabitants live on the 44 islands
of the Tuamotus. Therefore, the warning must quickly touch
a widely-scattered population.
Secondly, there are many interlocutors. Civil security is
shared between the French government, responsible for the
coordination of assistance efforts, and the Assembly of French
Polynesia, responsible for tsunami prevention. In addition, the
districts lack their own resources and the mayors, who are meant
to take over in the event of a warning being issued, are not
always reachable or even present in their districts, residing as
they often do in Tahiti.
Taking into account these constraints, it was decided to create a centralized, automatic alert system.
By the end of the year, 144 sirens will have been installed
in French Polynesia. Both the High State Authoriy and local
authorities will be able to set off these sirens. So as not to
be dependent on the local or international telephone or Internet
networks26(*), each siren may be activated via the Inmarsat mini-C satellite network.
The Inmarsat network
The Inmarsat network is the first global satellite
network for both fixed and mobile terminals. It is
used by all of the world's ships to transmit
distress and emergency signals, as well as for
commercial communications.
For the Pacific zone, it is made up of a
geostationary satellite and two backup satellites. If
need be, Inmarsat can transfer from the satellite in use
to one of the two backup satellites without having to
reconfigure or repoint the Inmarsat-C terminals. This
operation is therefore transparent for network users and
practically instantaneous.
In addition, the emission and reception of the
fixed or mobile terminals are not disturbed by
meteorological events, such as cyclones.
Finally, the Inmarsat-C terminals' incorporated
antennas require no pointing; they enjoy a vertical
reception of 360° and a below-horizontal reception
of up to 5°.
|
The sirens can be set off individually or in groups (an
island, an archipelago or all sirens in French Polynesia). The
sirens can be activated within 2 minutes by sending a message,
with the confirmation message arriving within 4 minutes (see
diagram below).
The manual activation process
Source: Assystem
Furthermore, the local authorities have portable satellite
telephones (also Inmarsat), allowing them to communicate
with the services of the High State Authority even in the event
of the local telephone lines being down.
The civil protection services have also passed an agreement
with Réseau France Outremer (RFO; "French Overseas
Network"): in the event of a tsunami warning, a message is
broadcast on television.
While the Assembly of French Polynesia is theoretically
responsible for tsunami prevention, the High State Authority is
also involved. During your rapporteur's visit to Tahiti, an
information brochure entitled "tsunami warnings in French
Polynesia" had just been published. Finally, in the Marquesas
and Austral Islands, full-scale training exercises are
organized, along with the evacuation and transfer of the
population.
B. A RISK THAT BEGAN TO BE TAKEN SERIOUSLY IN THE OTHER BASINS FOLLOWING THE TSUNAMI OF 26 DECEMBER 2004
While the scientific community and several international organizations27(*)
were already interested in tsunamis phenomena before the
Sumatra catastrophe struck, it must be admitted that the general
public only became aware of this hazard then.
1. The "shock" of Sumatra
Several factors explain the veritable shock provoked by the
tsunami that ravaged the Indian Ocean on 26 December 2004:
- Its uniqueness, with regard to both its size and the
number of victims. With a magnitude of 9.3, the earthquake which
provoked the tsunami was the second most violent earthquake
ever recorded, with a fracture zone 1,200 kilometres long. In
addition, the tsunami claimed 250,000 victims and displaced more
than one and a half million persons on the coasts of twelve
countries.
- The date on
which this event occurred and the immense media coverage it
attracted: the Christmas season is supposed to be a happy and
festive time of the year. Therefore, this natural disaster
strongly affected the world's population, generating an
unprecedented show of generosity: private individuals donated
more than €1.5 billion to humanitarian organizations. The media
certainly contributed to this generosity, by broadcasting only
hours after the tsunami struck footage for the most part
recorded by private individuals via their digital cameras or
cell phones, which showed this wave submersing the beaches and
seaside resorts. This event, therefore, quickly took on a
planetary dimension, all the more so considering the many
Western tourists who figured among the tsunami's victims.
Also, the fact that the Indian Ocean had, up until then,
been considered a relatively tsunami-safe zone generated
increased public awareness.
a) The realization that all basins are vulnerable
Statistically speaking, the Indian Ocean is considered the
safest ocean basin with regard to tsunamis, since it
accounted for only 4% of tsunamis generated during the 20th
century. However, the tsunami of 26 December 2004 claimed more
victims than all other (known) tsunamis combined since ancient
times.
In addition, it
served as a reminder that certain regions that had not been
struck by a tsunami in human memory had nevertheless been
completely devastated in the distant past, with the volcanic
eruption on Santorini being a good example.
b) Shedding light on the shortcomings of the tsunami-risk prevention system
The Sumatra tsunami above all revealed enormous shortcomings with regard to mitigating the tsunami risk.
First of all, the images showing tourists playing in those
areas where the sea had withdrawn revealed the public's
complete ignorance of this phenomenon and its manifestations.
Secondly, scientists were
surprised by the violence of the earthquake that had generated
the tsunami and it became clear that, outside the Pacific zone,
the tsunami phenomenon was not well understood due to
insufficient research in this domain. For example, few
catalogues of past tsunamis per basin had been published and the
potential sources of tsunamis had not been systematically
recorded and even less frequently analyzed in order to
establish tsunami-exposure maps.
Finally, many observed that if a warning system had been in
place, thousands of human lives could have been saved. The
international community, under the aegis of UNESCO, therefore
decided to complete the existing tsunami warning system and
extend it to all zones.
2. The desire for an effective tsunami warning and mitigation system that covers all basins
The international community estimated that setting up an
effective warning system for the Indian Ocean, the Caribbean
and the Mediterranean required, on the one hand, the creation of
intergovernmental groups for each basin (following the example
of the ICG/Pacific) and, on the other hand, increased scientific
research to better understand tsunamis in these regions.
a) The creation of three new intergovernmental groups
Following the tsunami of 26 December 2004, international
cooperation grew considerably in order to establish a
worldwide tsunami warning and mitigation system. The impetus
came during the 3rd World Conference on Disaster
Reduction, which took place in Kobe (Japan) in January 2005: a
plenary session was dedicated to the creation of a warning
mechanism for tsunamis in the Indian Ocean.
Taking into account its experience in the Pacific, UNESCO
was put in charge of coordinating the set up of the tsunami
warning system for the Indian Ocean. The IOC organized two
ministerial-level meetings in February and March of 2005, which
were attended by most countries of the Indian Ocean zone.
In addition, a "tsunami unit" was set up within the IOC in
January 2005, to support the actions of the newly created
intergovernmental coordination groups. In particular, this unit
organized the initial preparatory meetings, as well as the
evaluation visits in more than 18 Indian-Ocean countries.
In June 2005, the 23rd
General Assembly of the Intergovernmental Oceanographic
Commission adopted three resolutions for the creation of three
regional coordination groups:
- The Intergovernmental Coordination Group for the Indian
Ocean Tsunami Warning and Mitigation System (ICG/IOTWS),
which groups together 28 countries, including France, which is
present in this basin via La Réunion and Mayotte.
- The Intergovernmental Coordination Group of the Tsunami
Early Warning and Mitigation System in the North Eastern
Atlantic, Mediterranean and Connected Seas (ICG/NEAMTWS), made
up of 64 countries, including France.
- The Intergovernmental Coordination Group for the Tsunami
Warning System in the Caribbean and Adjacent Regions
(ICG/Caribbean-TWS), made up of 27 countries, including France,
which is present in this basin via Guadeloupe, Martinique,
French Guiana and Saint-Martin.
The final structure of these three warning systems should
be identical and based largely on the Pacific warning system.
The structure of the tsunami warning system
Source: IOC
Each country is responsible for collecting and processing
the national data from its seismic stations and tide gauges.
Each country must also ensure that this data is accessible in
real time to all members of the warning system. In addition, the
countries must carry out the necessary computer simulations to
better understand this hazard, to identify the exposure zones,
and to establish tsunami and inundation maps.
The data thus collected is transmitted in real time either
directly or by the countries to one or several regional
tsunami watch centres.28(*)
These centres are responsible for analyzing the earthquake data
(localization of the earthquake and estimation of its
depth, magnitude, date and origin time), in order to determine
if a tsunami risk indeed exists. If the answer if yes, the
regional centres send a warning message indicating the hour of
arrival and the concerned zones to the Focal Points of the
member states. The regional centres will also use the data
relative to the sea level to confirm the presence of a tsunami
and either refine their forecasts or cancel the warning.
Focal
Points and National Contacts for the Intergovernmental
Oceanographic Commission's warning system.
· The ICG Tsunami Warning Focal Points
The Focal Point is the person to contact, reachable
24 hours a day, 7 days a week, and chosen by the
ICG-member government to receive and rapidly send
tsunami information. The IOC advises countries to choose
one or several bodies, rather than persons. The Focal
Point receives the bulletins and warnings issued by the
regional warning centres and passes them on to the
relevant emergency services (usually the civil
protection services). As far as France is concerned,
Météo France serves as the Focal Point in the Caribbean
Sea and the Indian Ocean, while LDG/Pamatai serves as
the Pacific zone's Focal Point. However, France
does not have an official Focal Point in the
Mediterranean, even though CEA would be the natural
choice.
· The ICG Tsunami National Contacts
The ICG Tsunami National Contact is the person
designated by the ICG-member state to act as its
representative in the coordination of international
tsunami warning and prevention activities. This person
is a key player in the national warning system
programme. He or she may be the Tsunami Warning Focal
Point, someone belonging to the country's national
disaster management organization, a member of a
technical or scientific body, or a representative of
some other tsunami warning-related organization. In the
Indian Ocean, the Caribbean and the Pacific, this
position is filled, respectively, by a representative of
Météo France, a representative of IPGP
("Paris Global Physics Institute") and a representative
of CEA. As of June 2007, France no longer has a National Contact for the Mediterranean zone.
Source: UNESCO/IOC
|
Finally, the Focal Points are responsible for transmitting
the regional centres' warning bulletin(s) to the national
authorities, so that the latter may take the necessary measures:
implementation of the specialized tsunami emergency plan (see
the analysis of the warning system in French Polynesia, below),
which mobilizes all parties liable to be involved in preventing
the tsunami and in crisis management after the tsunami; warning
the population; evacuating the beaches and coasts.
At this point, your rapporteur would like to emphasize the
fact that this system will only be truly effective when the
national civil protection services have access to precise
information on the expected effects of the announced tsunami. As
was explained above, these effects are very difficult to
predict, insofar as they depend on many different factors: the
position of the source, the tsunami's directivity, the coastal
bathymetry and topography. As a result, the regional centre's
general message will have to be refined by a national body. This
assumes an organization in France that is capable of
analyzing the issued bulletins and comparing the current event
with computer simulations, so as to specify those zones truly
exposed. Otherwise, the national authorities will be faced with
two types of risk: a false warning and the under estimation of
the risk if the tsunami amplification effects of certain zones
are not taken into account (see the high exposure of the
Marquesas Islands compared to that of the Society Islands,
including Tahiti).
In
addition, the tsunamis liable to affect France's Mediterranean
and Caribbean coasts are local or regional tsunamis, resulting
in very short reaction times (between a few minutes and a half
hour). Therefore, it is essential that the scientific
organization in charge of advising the public authorities on the
seriousness and localization of the tsunami risk be
continuously on-duty - 24 hours a day, 7 days a week - and enjoy
real-time access to the seismic data and sea-level
measurements.
The three
intergovernmental coordination groups have committed themselves
to laying the foundations of a warning system by the end of 2007
(nomination of the member states' Focal Points and National
Contacts; designation of regional and national warning centres).
By 2010, the warning systems should be operational and all
basins should be covered.
Each intergovernmental group has established an action plan and
created specialized work groups that are meant to meet with one
another on a regular basis. For example, the ICG/Caribbean-TWS
has created the following four groups:
- Tsunamis hazard assessment;
- Monitoring and detection system. This group is divided
into two subgroups specialized in seismology and sea-level
monitoring;
- Warning and communication;
- Emergency and training
Depending on the region, a yearly or half-yearly meeting is
organized, to record the progress made by the member states
and workgroups, and to define the group's future actions.
Other initiatives of the international community should
strengthen the effectiveness of the tsunami warning and
prevention systems.
These
systems should rely, in the midterm, on the sharing of
terrestrial observation means: the Third Earth Observation
Summit, held in February 2005, agreed to a 10-year
implementation plan for a Global Earth Observation System of
Systems (GEOSS29(*)).
At the European level, this system will be able to depend
on the GMES (Global Monitoring of Environment and Security)
initiative.
The GMES initiative
Initiator
|
The European Space Agency, the European Union.
|
Participants
|
The European Space Agency, the European Union (the
European Commission and member states).
|
Status
|
Currently being developed.
|
Objectives
|
Create an autonomous, multi-level (local, regional,
global) European monitoring system for the
environment and security, in support of European policy
(on the environment, agriculture, etc.) and the EU's
international commitments.
|
Implementation of initial services
|
2008
|
Source: CNES
According to the information obtained by your rapporteur,
the last general assembly of the IOC in June 2007 sanctioned
the idea of cooperation between the four regional tsunami
warning systems, as well as the necessity to integrate the
tsunami warning system into a more global system that would
encompass the warning and mitigation of all oceanic risks
(tempests, cyclonal swells, typhoons, cyclones, rising sea
level).
Furthermore, the
policy of increasing public awareness and education with regard
to the tsunami risk has authority to be carried out within the
framework of the International Strategy for Disaster Reduction
(ISDR).
International Strategy for Disaster Reduction (ISDR)
This initiative, supported by the United Nations
(UN), is meant to help communities to better
withstand natural disasters by considering risk
reduction an essential part of sustainable development.
The strategy favours four lines of action:
- Raise public
awareness of the notions of natural-disaster risk,
vulnerability and reduction.
- Encourage decision makers at every level to take
measures to predict and mitigate the impact of
natural disasters.
- Encourage interdisciplinary and intersectorial
partnerships all over the world, for a better
understanding of the risks and of the measures under
consideration.
- Further scientific understanding to reduce the risks.
To carry out its programme, the ISDR relies on two organizations:
The ISDR's special team plays the primary role in
the elaboration of disaster-prevention policies.
This team, managed by the Deputy Secretary General
of the UN's Office for the Coordination of Humanitarian
Affairs, gathers together 25 UN, international, regional
and civil-society organizations. Twice yearly, it meets
in Geneva to debate problems of shared and global
interest related to disaster prevention (climate
variability, rapid warning systems, vulnerability
and risk analysis, fires in wild areas, droughts,
etc.).
The ISDR "interorganizational" secretariat serves as
an international exchange centre for information on
disaster prevention. It organizes public awareness
campaigns and publishes articles, revues and other tools
to promote natural disaster prevention.
Source: UN
|
Finally, the rapid and reliable transmission of tsunami
warning system data demands close cooperation with the World
Meteorological Organization (WMO). This United Nations body
specialized in meteorology manages the Global Telecommunication
System (GTS), whose objective is to rapidly collect, exchange
and transmit meteorological observation data. The GTS is used to
transmit tide gauge data and warning messages.30(*)
b) A strong increase in funding for tsunami-related research
At both the national and European Commission level, the
Sumatra tsunami led to the funding of numerous tsunami-related
research projects.
In 2005,
the ANR (France's National Research Agency) launched its
Telluric Disaster and Tsunami Programme (CATTELL), in order to
develop fundamental research on those phenomena generating great
telluric disasters. Four main lines were established:
- Seismotectonic risks: Promoting research on active
continental and underwater faults, decrypting the history of
seismogenic zones, modelling the propagation of seismic waves,
early warning systems for earthquakes, and the seismic
vulnerability of buildings/structures;
- Tsunami-related risks: Selected projects must study
tsunami-generating processes and technological research on the
tsunami warning systems;
-
Gravity-related risks: Research on the processes of terrestrial
and submarine landslides, physical phenomena of flows/slides,
and technology related to the monitoring of these phenomena;
- A transversal line of study:
Supporting technological and methodological research on these
natural risks and developing the socio-economic dimension of
early warning systems.
In 2005, 17 projects were selected for a total budget of
€5.17 million. 61% of the projects were related to seismic risk,
but tsunami-related risks represented the second most funded
theme, accounting for 17% of the financed projects.
In 2006, €4.2 million were attributed to the CATTELL
Programme. 14 projects were selected, with 69% of the funding
going to earthquake-related studies; no tsunami-related study
was selected.
The European
Commission also financed numerous research programmes following
the Sumatra tsunami of 26 December 2004.
Certain projects had already been carried out prior to this
devastating tsunami. GITEC (Genesis and Impact to Tsunamis
in the European Community) and GITEC TWO (Tsunami Warning and
Observations) had allowed for the creation of a European tsunami
catalogue (with 228 events recorded from 6000 B.C. to 2003
A.D.) and the improvement of simulation techniques. In addition,
several experimental tsunami warning systems had been tested
off the coast of Portugal, in the Ionian Sea and in the
Peloponnese.
Likewise, the
BIGSETS (Big Sources of Earthquake and Tsunami in South West
Iberia) project improved our understanding of the origins of the
1755 tsunami that devastated Lisbon.
In the 6th
Research Framework Programme (2002-2006), €48 million were
dedicated to natural disasters, €7.45 million of which went to
the study of tsunamis within the framework of three projects:
TRANSFER, NEAREST and SEAHELLARC.
The TRANSFER (Tsunami Risk and Strategies For the European
Region) project enjoys funding of €3.3 million and groups
together 29 partners. The project began 1 October 2006 and will
continue until April 2009. Its objective is to improve our
understanding of tsunami propagation in the Mediterranean and
help set up a tsunami warning system for this zone. 9
workpackages have been formed around the following themes:
- Improving and updating the
European tsunami catalogue and integrating it into the global
tsunami catalogue;
-
Identifying and characterizing the seismic and nonseismic
sources of tsunamis in the European-Mediterranean zone;
- Analyzing the current seismic and tide gauge observation
and data-processing systems, as well as identifying the
necessary adjustments for setting up an effective tsunami
warning system;
- Improving
tsunami modeling, for it to better take into account the
propagation and coastal impact of tsunamis.
In addition, seven geographical zones have been chosen for
the application of tsunami scenarios: inundation maps will
be created and warning and prevention plans established.
The NEAREST (Integrated observations from NEAR shore
sourcES of Tsunamis) project has a budget of €2.8 million and
groups together 11 partners. Its objective is to identify and
characterize those sources liable to generate local tsunamis in
the Gulf of Cadiz. An underwater observatory equipped with
seismic and pressure sensors will be installed and serve as a
prototype for a tsunami warning system. New simulations will be
carried out in the Algarve zone, which was strongly affected by
the tsunami of 1755 and new inundation maps will be drawn up.
Likewise, the objective of
the SEAHELLARC (Seismic risk Assessment and mitigation scenarios
in the western HELLenic ARC)31(*)
project is to set up a network of land and sea-based sensors to
better observe the seismicity of the Hellenic Arc and any
eventual tsunamis. The zone's bathymetry will be precisely
mapped, in order to identify the area's faults and those zones
where landslides are liable to occur. The objective is to
identify all tsunami sources. In addition, a study on tsunami
vulnerability will be carried out on the town of Pylos, which
will serve as a base for setting up a tsunami prevention and
warning plan.
Furthermore,
other projects financed by the European Commission indirectly
contribute toward the setting up of an effective tsunami warning
system.
For example, the objective of the SAFER32(*)
project is to develop civil-protection tools to allow for
an earlier warning, above all in densely populated areas. In
particular, this project seeks to create new algorithms for the
rapid localization of earthquakes and characterization of
faults. In addition, new tools will be developed for the
real-time creation of warning maps, as well as simulations of
damages caused by the earthquake.
Earthquakes that occur in the European-Mediterranean region
are currently recorded by 100 different observation systems
managed by 46 countries. The objective of the NERIES (Network of
Earthquake Research Institutes for Earthquake Seismology)
project is to bring all of these monitoring systems together
into a single network, to improve data access, and to harmonize
data distribution and storage.
Moreover, the ESONET (European Seas Observatory Network of
Excellence) project proposes laying the groundwork for a marine
component of the Global Monitoring for Environment and Security
(GMES) programme, consisting of a network of permanent,
multi-disciplinary observatories installed on the sea floor in
key zones on the European continental margins and allowing for
continuous geophysical, biochemical, oceanographic and
biological monitoring. ESONET will pay particular attention to
the oceanic margins beyond the limit of the continental shelf
and down to depths of 4,000 metres: this zone is not nearly as
well known as the continental shelf itself and is not covered by
the current systems for gathering oceanic data. The
European continental margins extend for some 15,000 km, from the
Arctic Ocean to the Black Sea, covering a surface area of
nearly 3 million km². The EMSO ( European Multidisciplinary Seas Observation)
project is responsible for installing the observatories on the
sea floor. 5 sites (each of which has its own specific research
theme) have been identified. The Liguria Sea site has the
authority to attach its measuring devices to the ANTARES33(*)
project cable; this observatory will study the geophysical
risks near densely populated zones and test devices either
installed on the seafloor or used for core sampling.
Finally, the 6th
Research Framework Programme has provided €4 million to the
DEWS (Distant Early Warning System) project, supported by the
Information Society and Media Directorate-General of the
European Commission. Its objective is to complement the warning
system currently being set up by the Germans in
Indonesia34(*),
by using information technology to increase the performance of
the sensor networks, decrease the warning messages'
transmission times, and improve cooperation not only between
countries, but also between the concerned authorities.
3. Unequal results
a) The Indian Ocean: a successful international mobilization effort
Following the Sumatra tsunami, the countries of the Indian
Ocean touched by this natural disaster were the object of an
unprecedented show of solidarity. The United States donated
€1.95 billion, €714 million of which came from the government
and €1.2 billion from private donators. Germany was the second
largest contributor, with €536 million being donated by the
German government and €553 million in private donations. In
addition to donating money for humanitarian aid and the
reconstruction of the devastated areas, numerous countries
wanted to help set up a tsunami warning system for the Indian
Ocean. As has already been pointed out, Germany committed €45
million to the installation of a warning system in
Indonesia. Likewise, Japan has installed 23 wideband seismic
stations in this country.
Since the tsunami warning system in the Indian Ocean is not yet
operational, the Hawaiian (PTWC) and Japanese warning centres
provide this region with information messages35(*) in the interim.
The Intergovernmental Coordination Group for the Indian
Ocean Tsunami Warning System has already met four times. During
its last meeting in Kenya in February and March of 2007, the
group observed that important progress had been made.
The assessment visits for evaluating the countries' ability
to set up warning systems, carried out between June and
September of 2005 with the funding of donor countries, proved
very effective. Thanks to the presence of experts sent by the UN
bodies (UNESCO, WMO and ISDR), these assessments helped raise
awareness among these countries, which then actively supported
setting up a warning system.
For example, most countries have begun installing the
necessary measuring devices for the analysis of tsunamis and the
real-time transmission of data. India is currently modernizing
its network of seismic stations and plans on installing 50 tide
gauges and 12 pressure sensors (tsunamimeters). In Indonesia, 67
of the planned 160 seismic stations already transmit their data
in real-time; 25 tsunamimeters and 80 tide gauges should
complete this system.
Certain countries have also already taken measures to alert
their populations. In Malaysia, sirens are to be installed in
densely populated areas. In Thailand, the national warning
centre for natural disasters can now interrupt the programmes of
the country's 14 television channels and numerous radio
stations in order to broadcast its messages.
In addition, training sessions on risk evaluation have been
organized in Dubai and on the drawing up of inundation maps
in Perth. Each workgroup has defined a precise programme of
action and there is a significant sharing of information between
the participants of each group. In this regard, the logistical
support provided by Australia - which, in particular, finances
the group's secretariat - represents an important asset.
Finally, a tsunami information centre, modeled after the
Hawaiian centre and financed by Canada, is to be set up in
Jakarta.
For all that, certain gaps remain and must be remedied by the ICG/IOTWS countries.
First of all, a test carried out by the tsunami warning
centre in Hawaii in February 2007 revealed certain malfunctions
in the reception of warning messages by the national Focal
Points; not every country was able to confirm having received
the warning message. In addition, this test demonstrated the
unequal effectiveness of the three communication tools used,
depending on the particular country: while transmitting the
message via the Global Telecommunication System necessitated
between 1 and 15 minutes, 10 to 15 minutes were required to
successfully transmit the message by fax and 1 to 59 minutes by
email.
Secondly, the
correct evaluation of the tsunami hazard when an earthquake
occurs in the region runs up against several difficulties: the
number of land and sea-based measuring devices providing real
time data remains insufficient; there are no high-resolution
bathymetric and topographic data for those areas near the
coasts; no paleotsunami study has been carried out to better
understand ancient events.
Furthermore, the national networks' integration into a regional
warning system is proving difficult. The sharing of seismic and
sea level data between the ICG/IOTWS countries remains very
partial, while the structure initially chosen for the system
(i.e., one or several regional centres issuing warning messages
to national centres) has been challenged. Indeed, the countries
do not want to be dependent on a single centre for the issuing
of warning messages for a precise geographical zone; instead,
they favour increasing the sources of information.
Therefore, the warning system will not be made up of "regional
tsunami warning centres", but rather "Regional Tsunami Watch
Providers"36(*) with which each country will pass an agreement in order to receive the issued bulletins.
Finally, much work remains to be done with regard to
warning the concerned populations. According to the information
obtained by your rapporteur, few countries have implemented a
national and local emergency plan defining the responsibilities
and missions of all concerned parties in the event of a tsunami.
The tsunami of 17 July 2006, which claimed more than 500
victims in Indonesia, revealed shortcomings in the warning
system: although PTWC had transmitted an information bulletin to
the Indonesian authorities, they were unable to protect the
population by rapidly broadcasting precise information on the
threatened coastal zones.
Despite these inadequacies, the assessment of actions
undertaken by the ICG/IOTWS is rather positive. It must not be
forgotten that this initiative was launched only two years ago
and that it took almost 40 years to set up a truly effective
tsunami warning system for the Pacific. The setting up of a
tsunami warning system in the Indian Ocean benefitted from an
unprecedented financial godsend from the many donor countries.
As of April 2005, it could also rely on the messages issued by
the Pacific centres and the experience accumulated by the
ICG/Pacific; it has also been able to profit from recent
technological advances (tsunamimeters, increasingly effective
computer models, etc.). However, a certain number of years will
be needed to not only set up an effective national and
international warning system, but also to build confidence
between the concerned countries and develop a regional system
based on cooperation and the sharing of data.
It should be pointed out that the structure of the Indian
Ocean monitoring systems is much simpler than those of the
other basins, as shown in the following map:
The different types of tsunami
liable to touch the Indian Ocean countries
- The zones circled in red are subject to local tsunamis.
- The zones delineated by dotted orange lines are subject to regional tsunamis.
- The zones circled in yellow are subject to distant tsunamis.
Source: CEA/DASE
Indeed, as compared to other regions whose countries are
threatened by local, regional and sometimes distant tsunamis,
all the Indian Ocean countries - with the exception of Burma and
India - are exposed to only one type of tsunami:
- Myanmar, the Andaman and Nicobar Islands, Timor, Iran and
Pakistan can be touched by local tsunamis. Therefore, for
the warning system to be effective, these countries must be
equipped with dense monitoring systems and very rapid warning
centres, with teams on-duty 24 hours a day, 7 days a week.
- Myanmar, Thailand, Malaysia,
Singapore, Sri Lanka, India, Australia and Oman are threatened
by regional tsunamis: they therefore have more time to react in
the event of a warning being given.
- Finally, the 16 countries located within the yellow
circle are exposed to teletsunamis: their monitoring systems can
therefore be less dense and their warning centres need only be
on-call.
As a result, the
overall investment and operating costs are (in proportion to the
size of the Indian Ocean) 3 to 5 times less than in the other
basins, whose countries must be equipped to face all types of
tsunami.
On the other hand,
the relative isolation of the various warning systems could
explain the difficulties encountered in trying to integrate the
national systems into a regional warning system.
b) The Caribbean: numerous obstacles to setting up an effective warning system
Since the creation of the Intergovernmental Coordination
Group for the Tsunami Warning System in the Caribbean, only
two meetings have taken place (in Barbados in 2006 and in
Venezuela in 2007) and little progress has been made.
First of all, the Caribbean zone suffers from several
disadvantages: it is a "multi-hazard" region (cyclones,
earthquakes, volcanic eruptions, tsunamis) made up of many small
islands and countries with meager financial and logistical
resources.
Since the
tsunami risk has long been ignored in this region, it is poorly
equipped with measuring devices capable of detecting tsunamis
and issuing reliable warning messages. Considering this zone's
significant seismic risk, several seismological networks exist,
even though certain regions, such as Mexico and Cuba, remain
poorly covered. Ultimately, each island will have to have a
seismic station, for the very rapid detection of earthquakes.
As regards the region's tide
gauges, it was observed during the last meeting that 60% of
these devices are out of service and that only a very few of
those that do function transmit their data in real time.
Source: Puerto Rico Seismic Network
In addition, this region demands very fast reaction times.
For example, a tsunami generated in the Virgin Islands will
arrive in one hour and fifteen minutes in Guadeloupe, but in
only 10 minutes if generated in Montserrat. Therefore, the
warning system methodologies used in the Pacific region, where
the distances covered are much greater, are simply not pertinent
for the Caribbean zone. However, the last conference revealed
that half of the zone's countries have yet to name their Focal
Point.
The group's actions
are considerably slowed down by the lack of financial means. The
ICG/Caribbean-TWS does have at its disposal the Caribbean
offices of the IOC in Cartagena (Colombia). However, contrary to
the ICG/IOTWS, it does not have any personnel specifically in
charge of managing its actions and, in particular, organizing
local work sessions: during the last meeting of 2007, it was
observed that three out of four workgroups had not met for over a
year, due to a lack of funding.
Finally, one must emphasize the difficulties related to the
at times difficult relations that exist between this zone's
countries, which constitute significant obstacles to setting up
a warning system based on the sharing of information. For
example, during the meeting in Venezuela, the Venezuelan
institute responsible for seismic research37(*)
announced that it did not want to take part in the
international tsunami monitoring system via the sharing of
seismic data.
Nevertheless,
the Caribbean zone does have an advantage: the presence of
American territories (Puerto Rico and the Virgin Islands) and
the proximity of Florida. Within the framework of its National
Tsunami Hazard Mitigation Program, the United States has taken
several measures originally intended to protect its own coasts,
but which also benefit the entire region.
First of all, beginning in 2006, it was decided that PTWC
and WC-ATWC tsunami warning centres would extend their
activities to the entire zone until a regional system was set
up.
Furthermore, Puerto
Rico quickly emerged as the most advanced country with regard to
tsunami preparedness. After launching, with the aid of the
ICG/Pacific, a tsunami warning and mitigation programme in 2000,
a tsunami warning system was established in 2003. Puerto Rico's
seismic station was put in charge of detecting
tsunami-generating earthquakes, in collaboration with PTWC.
This system has slowly but
surely been improved. In 2006, the United States Geological
Survey installed 9 seismological stations linked by satellite to
Puerto Rico's seismic network, in order to complete the
networks' coverage. Furthermore, one DART buoy was installed in
the Caribbean Sea, one in the Gulf of Mexico and two north of
Puerto Rico.
As a
result, even if Puerto Rico's seismic network does not yet meet
all the necessary conditions of a warning centre38(*),
in practice, it has been recognized as such by most countries
in the region. Indeed, more than 50 broadband seismological
stations in the Caribbean zone transmit their data in real time
to the Puerto Rican network. During the last meeting, Puerto
Rico's seismic network distributed to all participants a funding
request for €815,000 addressed to the American Congress in
order to ensure the operating costs of the future warning
centre for the period of 2007-2010.
c) The waiting game in the Northeast Atlantic and Mediterranean zones
The intergovernmental coordination group for the
Northeastern Atlantic and Mediterranean zone has already met
four times: in Rome in November 2005, in Nice in May 2006, in
Bonn in February 2007 and in Lisbon in late November 2007.
However, it would appear to be difficult to set up a tsunami
warning system for this zone.
The seismic coverage of the Mediterranean zone countries is
far from being homogeneous, with regard to both the number of
seismic stations and the type of seismometer installed. In
addition, many countries, particularly the North African states,
refuse to provide access to their data. However, the rapid
detection of an earthquake and the reliable localization of its
epicentre, depth and magnitude require a dense network of
seismometers, whose data is available to everyone. Insofar as
those sources liable to provoke a Mediterranean-wide tsunami are
located along the faults off the coast of North Africa, the
unaccommodating attitude of these countries constitutes a major
obstacle.
Furthermore, very
few tide gauge stations transmit their data in real time, which
means this information cannot be used to generate tsunami
warnings or verify whether a tsunami has indeed been induced. As
regards the most modern tide gauge stations (as well as many
seismic stations), data transmission is carried out not by
satellite but by Internet, even though this means of
communication may be disrupted by an earthquake.
The working group on instruments for measuring sea level
has selected some thirty particularly strategic tide gauges
and urged those countries responsible for managing and
processing their data to render them operational for the
detection of tsunamis39(*)
before the end of 2007. However, its success depends on the
goodwill of these countries, since no specific funding has been
set aside for this action. Therefore, this programme risks to
be delayed, considering the difficulty encountered by the
organizations responsible for the tide gauges in obtaining funds
for their improvement. For example, SHOM ("Marine Hydrographic
and Oceanographic Service"), responsible for improving the
performance of tide gauges located on the French coasts, has
already announced that, due to a lack of funding, only data from
Le Conquet tide gauge will be transmitted in real time in 2007.
List of tide gauges judged to have priority for the setting up of a tsunami warning system in the Mediterranean
Source: IOC
In addition to an unwillingness to share seismic data, the
setting up of an effective tsunami warning system meets with
the refusal of numerous North African countries to transmit
their tide gauge data.
Likewise, the lack of funds makes installing pressure sensors at sea difficult.
In addition to the question of tsunami detection, it seems
that no country has begun to elaborate a warning plan laying
out the measures to be taken by all the various authorities
responsible for civil protection. No inundation zone has been
delineated, no evacuation plan is operational. The warning
methods have not been defined (sirens, radio messages, etc.) and
no public awareness and education programme has been carried
out.
Your rapporteur has
observed that the European Union, represented by the European
Commission, was not involved in setting up the tsunami warning
system for the Mediterranean/Northeast Atlantic zone. This
absence is surprising for several reasons.
Firstly, this project is by its very nature European: all
the European countries are concerned, some because they
border the Mediterranean, the others because a significant
portion of their population spends its holidays on the coasts of
the Mediterranean countries.
In addition, this project necessitates the installation of
infrastructures (seismic stations, tide gauges, tsunamimeters)
that are useful to all the countries, but which still rely on
national funding. Therefore, the European Union should take
responsibility for a portion of this instrumentation via
European programmes; this would certainly accelerate the setting
up of a warning system.
Finally, this project will only become operational if the North
African countries decide to cooperate. The European Union can
encourage them to do so within the framework of its
European-Mediterranean policy.
In the opinion of your rapporteur, the elaboration of a
clear tsunami warning strategy for the Mediterranean/Northeast
Atlantic zone is confused by two additional factors: the
diversity of tsunami sources and the desire to create a
multi-risk system.
The
warning systems currently being set up in the Indian Ocean, the
Caribbean and the Mediterranean/Northeast Atlantic are designed
to detect regional tsunamis and teletsunamis; in other words,
tsunamis which are mainly provoked by earthquakes and whose
source is sufficiently distant to provide an interval of between
20 minutes and several hours before their arrival on the
coasts. For those coasts touched sooner (i.e., located nearer
the source), the planned warning system is not yet operational,
because the delays are too short and no country has decided to
automate its warnings using sirens.
However, research on the sources of Mediterranean-zone
tsunamis shows that the danger is not simply seismic in origin,
but also linked to landslides and volcanic eruptions. There is
therefore a significant risk of local tsunamis, even though this
risk cannot be suitably managed by the proposed system.
Therefore, certain countries are questioning the validity of
this system, because it does not address local tsunamis.
In the opinion of your rapporteur, this attitude is hardly
justified: considering the difficulties already encountered
in setting up a regional tsunami warning system, it would be
unrealistic to want to make the system operational at this stage
for local tsunamis. Indeed, local tsunamis demand a very dense
network of instruments and a permanent monitoring of zones of
"gravitational instability" and volcanoes, both of which can
only be ensured by the concerned countries. It should be pointed
out that in the Pacific system, PTWC also functions as the
local warning centre for Hawaii. Therefore, those countries of
the Mediterranean/Northeast Atlantic zone particularly
vulnerable to local tsunamis will eventually be induced to
develop national or even local warning systems. For instance,
Italy has installed a permanent monitoring system for Stromboli,
following the tsunami of 30 December 2002.
Furthermore, this geographical zone
(Mediterranean/Northeast Atlantic) is not homogeneous in its
exposure to tsunamis. Northern Europe is less concerned by
tsunamis than it is by storm surges. Therefore, these countries
have accepted to participate in setting up a tsunami warning
system only if the said system takes into account all risks of
oceanic origin.
The
supporters of this multi-risk approach believe that it should be
easier to finance instruments for measuring sea level, because
they can be used for the detection of several types of risk.
However, extending the warning system to include several risks
could also delay its implementation. Indeed, the necessary
scientific knowledge is not the same: tsunami detection relies
on a seismological network, while tempests fall within the
competence of the meteorological services. Likewise, the
prevention plans are independent, insofar as the necessary
reaction times vary greatly. Even though establishing a system
to manage a single risk proves to be a rather laborious process,
requiring many meetings before any consensus can be formed, the
decision-making process risks to be slowed down even further if
other hazards must also be taken into account.
***
Since the Sumatra tsunami, the international community has
realized that the tsunami risk is not limited to the
Pacific, but rather concerns all of the world's oceans and seas.
Therefore, each basin has set about setting up a tsunami
warning system.
The results
have been unequal: the countries of the Indian Ocean, still
very much affected by the disaster of 26 December 2004 and the
three following tsunamis40(*),
remain strongly motivated. However, in the Caribbean and
Mediterranean/Northeast Atlantic zones, with the populations
having gotten over the initial shock provoked by Sumatra, most
of these countries (including France) now seem reticent to
invest in a permanent warning system, considering the rarity of
the hazard.
III. FRANCE'S POSITION: A WAIT-AND-SEE POLICY THAT IS UNACCEPTABLE CONSIDERING THE SERIOUSNESS OF THE STAKES
Via its overseas départements
and territories, France is present in all of the world's
oceans, which should encourage it to play a central role in
the setting up of tsunami warning systems. In reality, once the
initial shock provoked by the Sumatra catastrophe had faded
away, the political will to take action soon followed suit,
leaving the technical services on their own and without the
necessary means to assume the commitments taken by France only
just over two years ago.
A. A HIGH VULNERABILITY TO TSUNAMIS WHICH SHOULD INDUCE FRANCE TO MAKE A STRONG COMMITMENT
All French coasts are concerned by tsunamis; therefore, it
is in the country's interest to develop an international
warning system.
1. Important security stakes
a) A particularly high vulnerability due to its geography
France's Exclusive Economic Zones (ZEE) cover more than 10
million km² in the Atlantic, Indian and Pacific Oceans.
Therefore, France is second only to the United States.
Conversely, this means France is particularly vulnerable to tsunamis.
Metropolitan France has 5,800 km of coastline. As regards
its Mediterranean coast, the following events have been
recorded:
- On 20 July 1564, an earthquake provoked an inundation in Antibes and caused damages in Nice.
- On 4 February 1808, an ebb and flow were observed in Marseilles following an earthquake.
- On 9 December 1818, an earthquake provoked violent waves in Antibes.
- On 23 February 1887, an earthquake in the Liguria Sea
provoked a retreat of the sea followed by waves of up to 2
metres in Cannes and Antibes, inundating the beaches and causing
material damages.
- On 16
October 1979, the collapse of a section of the Nice Airport
generated waves 3 metres high in Antibes.
- On 21 May 2003, the tsunami generated by the
Boumerdès earthquake in Algeria (with a magnitude of 6.8 on the
Richter Scale) caused damages in several French harbours.
The last two events are symptomatic of the types of tsunami
that could affect the French Riviera in the future.
Firstly, a landslide is liable to provoke a local tsunami,
with a very short propagation time. In the case of the Nice
Airport, the accident was undoubtedly caused by both the
construction work and the zone's instability. Generally
speaking, the Liguria Sea coast (from Fréjus to Menton for
France) is deemed unstable and deep, resulting in a maximum risk
level.
Secondly, the
geodynamic context of the Mediterranean coast makes this a
dangerous zone. An earthquake provoking a landslide or an
underwater earthquake could generate a tsunami that would make
the event even worse. Such an earthquake could occur in the
Liguria Sea, where there are active faults. It could also occur
in Algeria. The Boumerdès earthquake occurred on the border
between the Eurasian Plate and the African Plate, in a region
where the African Plate moves in a northwesterly direction
against the Eurasian Plate, at a speed of a few millimetres
per year. The relative displacement of the plate creates a
tectonic environment favourable to high-magnitude earthquakes
that could generate tsunamis several metres high, with very
short propagation times (no more than one hour).
France also has more than 12,000 km of overseas coasts, in
every ocean of the world. The tsunami risk is especially
high in La Réunion, the Pacific and the West Indies.
Some 7 hours following the Sumatra earthquake of 26
December 2004, the tsunami had reached the coast of La Réunion
with waves of up to 2.5 metres, causing nearly €500,000 worth of
material damages.
In the
Pacific, while the tsunami risk is not ignored in French
Polynesia, up until now, it has nevertheless not been the
subject of any monitoring programme in Wallis and Futuna and New
Caledonia. However, several events testify to the reality of
this risk in these two regions.
Tsunamis observed in New Caledonia
DATE
|
PLACE OF ORIGIN
|
REMARKS
|
28.3.1875
|
Earthquake (8)
Vanuatu
|
Devastating tsunami in Lifou.
|
4.10.1931
|
Earthquake (7.9)
Solomon Islands
|
1.5 m tsunami in Hienghene, boats capsized.
|
19.7.1934
|
Earthquake (7.8)
East Solomon Islands
|
1.3 m tsunami in Hienghene, Touho.
|
21.7.1934
|
Earthquake (7)
East Solomon Islands
|
Tsunami in Hienghene, Touho, Thio.
|
1951
|
Exact date and origin unknown.
|
Tsunami north of Ouvéa.
|
1993
|
Earthquake (6.3)
Futuna
|
Local tsunami that did not cause any damage.
|
1 April 2007
|
Earthquake (8.3)
Solomon Islands
|
Tsunami in Hienghene, Poindimié and Touho.
|
Source: CEA, IOC
The tsunami history of the West Indies is still not well
known; however, we do know that the Lisbon earthquake of 1755
generated 3 to 6-metre-high waves there. This region's
seismicity is dominated by ruptures between the North Atlantic
and Caribbean Plates, with the first sinking below the second at
a speed of 2 cm per year. This region is also highly volcanic.
The past decade has been marked by several events:
· On 21 November 2004, an earthquake occurred off the coast of Guadeloupe, some ten kilometres south of Les Saintes. With a magnitude of 6.3, this was the strongest earthquake to have hit the archipelago since 1897. A "hollow" formed on the sea floor, inducing water movements that generated a tsunami with a propagation velocity of some 100 km/h. The water retreated by some 80 metres. Measurements taken by geologists a few weeks later on the neighbouring coasts showed, by the debris left by the tsunami, that the sea had risen several metres in certain locations along the southern coast of Les Saintes. Luckily, the tsunami caused only material damages.
· Successive collapses of the volcanic dome on the neighbouring island of Montserrat generated tsunamis on the coasts of Guadeloupe in 2003 (with a height of 8 m in Montserrat and 70 cm in Guadeloupe) and in 2006 (with waves of up to 1 m in Guadeloupe).
The
Montserrat volcano's landslides have sent 200 million m3 of
volcanic material into the sea since 1997. However, it has been
demonstrated that other volcanoes in the West Indies have
generated much larger landslides in the past. For example, Mount
Pelée in Martinique sent several km3 of rock into the sea
100,000, 25,000 and 9,000 years ago. A simulation has shown that
a new collapse of this volcano (of some 1 km3) would generate a
wave 10 to 20 metres high in the region. As for Mount Soufrière
in Guadeloupe, this volcano has collapsed every thousand years
or so for the past 8,000 years, the last time being 400
years ago.
Finally, there
is an active underwater volcano near Grenada, called "Kick'em
Jenny", that could also have a devastating impact. This volcano
is currently located 180 m below sea level, but should one day
form a new island.
In addition, the high population density of the French
coasts, due to their high level of urbanization and
industrialization, renders these coasts very vulnerable. The
following examples are revealing:
In 1999, the population density of metropolitan France's
coastal areas was 272 inhabitants per km², compared to a
national average of 108 inhabitants per km². In certain
locations, this figure can rise to as high as 2,500 inhabitants
per km² along the French Riviera in the Alpes-Maritimes
département, which welcomes nearly 10 million tourists each
year41(*), with peaks of up to 750,000 tourists per day during the summer.
As for Tahiti, 30,000 persons can be found on the coastal
roads leading into and out of Papeete between 6:30 and 8:30
a.m. every day. The island's oil depots are located at the
harbours, and its airport and "Postal and Telecommunications
Service" are both on the coast.
2. Significant advantages
France can rely on its experience in Polynesia and its
leading geoscientific and oceanographic organizations to help it
set up international tsunami warning systems.
a) The precedent in Polynesia
France has acquired precious experience in French Polynesia
through the management of the Polynesian tsunami prevention
centre. It managed to set up a national, operational and
autonomous warning system that is capable of managing the entire
warning chain, from detecting earthquakes to evacuating the
concerned population. This system has slowly been perfected over
the years to take into account inadequacies observed during
past tsunamis, as well as scientific advances.
Therefore, this experience could be applied to the setting
up of warning systems in the other basins. For example, the
decision matrices42(*)
and specialized emergency plans are two fundamental tools that
could be borrowed and adopted to the specificities of each basin
and member state.
b) Leading organizations in the geosciences and oceanography fields
Furthermore, France has excellent organizations that can
actively improve the effectiveness of the tsunami warning
systems, as long as they are provided with the necessary means
to do so.
Rather than
listing all of the research institutes and universities that
France can depend on, your rapporteur will simply name five
bodies which appear to him to be essential for setting up a
tsunami warning system: CEA, IPGP, SHOM, IFREMER ("French
Research Institute for Sea Exploration") and BGRM.
CEA, through its DASE ("Analysis, Surveillance and
Environment Department"), already plays a central role in
tsunami prevention in French Polynesia and is meant to
eventually become the national tsunami warning centre within the
framework of the Mediterranean/Northeast Atlantic, Indian Ocean
and Caribbean warning systems.
In addition to managing the 6 seismic stations within the
framework of the Comprehensive Nuclear-Test-Ban Treaty, CEA
ensures nation-wide seismic monitoring and is responsible for
informing the civil protection authorities as soon as an
earthquake of magnitude 4 or greater has been detected on French
territory. To carry out this mission, CEA has at its disposal a
digital seismic network made up of 40 stations, whose data is
transmitted in real time to the national data centre in
Bruyères-le-Châtel. This network is monitored by an automatic
monitoring system liable to broadcast technical warnings in the
event of a software or transmission-system failure. CEA also has
a team of engineers on-call 24 hours a day, 365 days a year,
made up of a dozen seismologists, three computer engineers
and some ten engineers responsible for monitoring and
maintaining the networks. These personnel enjoy all the
necessary means for network maintenance and data processing
(laptop computers, digital communication links, vehicles, etc.).
CEA's offices also host
the European-Mediterranean Seismological Centre (EMSC). This
centre collects in real time the seismic bulletins issued by 59
different bodies and networks using data from 1,700 stations,
which are then immediately archived and broadcast via its
website. The centre makes available not only the list of
earthquakes (with their location, depth and magnitude), but also
maps allowing for their visualization. In addition, depending
on the observed magnitude, the EMSC is responsible for issuing
warning messages to the Council of Europe and the civil
protection centres, according to a predefined list.
Furthermore, CEA is specialized in tsunami modelling and
has carried out numerous studies for French Polynesia,
including the elaboration of the region's tsunami exposure map
and a historic study of French Polynesian tsunamis from 1837 to
the present day.
Finally,
CEA staff includes one of the few internationally renowned
tsunami experts, who participated during several years in
efforts to improve the tsunami warning system in the Pacific, in
particular as chairman of the ICG/Pacific, and is currently
serving as an expert advisor in the setting up of warning
systems for the three other basins.
IPGP is also an essential interlocutor for setting up
warning systems in the Caribbean and in the Indian Ocean, where
it is responsible for monitoring two types of tsunami-generating
phenomena: volcanoes and earthquakes.43(*)
First of all, IPGP's observatories are responsible for
monitoring the volcanic activity of Mount Soufrière in
Guadeloupe, Mount Pelée in Martinique and Piton de la Fournaise
in La Réunion.
In the West
Indies, IPGP has a second mission which consists of continuously
monitoring and recording the regional seismicity (for
Martinique, Guadeloupe and the nearby islands) linked to the
tectonic activity of the Lesser Antilles island arc. The
objectives are 1) to alert the authorities of the
characteristics of observed earthquakes and the possible
after-shocks that could occur and 2) to establish over the long
term the spatiotemporal characteristics of the regional and
local seismicity, in order to contribute to the elaboration of
seismic maps.
Furthermore,
IPGP is responsible for the GEOSCOPE programme (i.e., the French
component of the broadband seismic measurement networks).
GEOSCOPE is made up of 28 operational stations44(*), 13 of which transmit their data in real time45(*) (in particular, one in La Réunion, one in Martinique, one in Hawaii, one in Djibouti46(*),
one on Kerguelen Island, one in Algeria, one in Australia and
one in the Marquesas Islands). The data collected by the
seismic station in New Caledonia is transmitted in less than
two hours. This network helps in the localization of earthquakes
all over the world. Because of the quality of its stations and
their geographical distribution, it is also closely involved in
setting up the international tsunami warning systems, in
particular those of the Indian Ocean and the West Indies.
IFREMER also plays a central role in setting up a tsunami
warning system. This public body, created in 1984, plays a
dual industrial-commercial role and contributes, through its
work and expertise, to our understanding of the oceans and
oceanic resources, the monitoring of marine and coastal
environments, and the sustainable development of marine
activities.
To these ends,
it designs and implements observation, experimentation and
monitoring tools and manages France's oceanographic fleet for
the entire scientific community. As a result, it is closely
connected to all projects concerned with the sea and requiring
specific instrumentation, such as the ANTARES project (the
installation of a thousand photodetectors, whose data is
transmitted by cable), the installation of a seabed seismometer
in partnership with Géo-Azur, and the various bathymetric
projects.
Indeed, it is
internationally renowned for its skills and experience.
Therefore, it was put in charge of testing the tsunamimeters
developed by the Germans for the Indonesian warning system.
Its expertise in geophysical
risks, in combination with its exploration capacities make it an
essential partner for setting up tsunami warning systems in the
Mediterranean, Caribbean and Indian Ocean.
SHOM, converted into a public establishment last May, also
has a fundamental role to play within the framework of its
mission to support public maritime policies. Its network of tide
gauges and its cartographic and bathymetric data are
indispensable tools in setting up an effective tsunami warning
system.
Finally, BRGM
constitutes an important partner. A public industrial-commercial
body placed under the authority of the Ministry of Higher
Education and Research and the Ministry of the Environment and
Sustainable Development, BRGM's activities with regard to
natural risks concern the understanding and modelling of
phenomena, the evaluation of the corresponding dangers,
monitoring, studying the vulnerability of exposed sites, risk
and prevention analysis, crisis preparedness, information
diffusion, and training. Therefore, via its synthetic studies,
BRGM provides national and local authorities with the necessary
tools for natural risk prevention and the resulting
territorial development.
3. A strong mobilization following the Sumatra tsunami
Following the tsunami that devastated the Indian Ocean on
26 December 2004, France took several measures to protect its
coasts from a possible tsunami.
a) The creation of a Post-Tsunami Interministerial Delegation
The Sumatra tsunami resulted in a significant mobilization
in France, at both the private and NGO level (€312 million
were collected in donations) and the public institutional level
(ministries and local governments).
An interministerial body was created in mid-January 2005
for the rehabilitation and reconstruction phase: DIPT
(Post-Tsunami Interministerial Delegation), which became CPT
("Post-Tsunami Coordination Commission") in July 2005. Dependent
upon the Ministry of Foreign Affairs, DIPT ensured the
coordination of interministerial initiatives, the coordination
with the local governments and NGOs, and the allocation of
public funds to the various reconstruction projects.
The role of DIPT (Post-Tsunami Interministerial Delegation)
Created on 19 January 2005 to coordinate France's
actions, this institution followed other
institutional endeavours, such as the Fauroux Mission
for the Balkans. With its offices located in the
Ministry of Foreign Affairs, the Interministerial
Delegation was an interministerial body directed linked
to the Prime Minister's office. The plan put into action
to create DIPT enjoyed significant political clout and
was truly effective. It was carried out by a team made
up of both diplomats and representatives of the
concerned ministeries, organized around a structure
strongly supported by the DGCID (Directorate General for
International Cooperation and Development). The
interministerial consultation procedures were very
quickly established in order to ensure a high
quality of advice and the transparency of the processes.
The system of regular interministerial meetings
organized by the Junior Minister for Foreign Affairs
rapidly spread information on the creation of DIPT and
the "one-stop" system.
Three important concepts governed the strategic functioning of DIPT:
- The budgets are allocated on a yearly basis (the "one shot" concept).
- The budgets must be rapidly allocated to have a
visible, marked effect for the concerned
populations while the ponderous bilateral and
multilateral mechanisms are still being mobilized.
- The allocated budgets must act as levers, by
providing access to additional funding (European,
American).
Project selection has greatly benefitted, in terms
of both speed and quality, from the setting up of
this rather innovative interministerial process.
A set of criteria was established in an
interministerial manner following the first
interministerial missions:
- The geographical criteria which emphasized
Indonesia and Sri Lanka, but not exclusively
(programmes were also funded in India and the Maldives).
-
The thematic criteria: the initial intervention themes
(children and education, health, water and
decontamination, risk prevention and crisis management)
were also reconsidered with an emphasis placed on those
aspects relative to boosting the affected economies.
Six types of player were mobilized:
- French NGOs with which coordination meetings were
held every three weeks on average, as well as
before and after each on-the-ground mission.
- French research or health institutions.
- National or local public structures in the concerned countries.
- Local NGOs (via calls for proposals for
micro-projects in Indonesia and Sri Lanka).
- The United Nations; in particular, the UN's emergency-relief agencies.
- The International Committee of the Red Cross in
the case of an extreme emergency.
Each institution wishing to make a project proposal
was able to do so via five "channels": the
Humanitarian Aid Commission of the Ministry of Foreign
Affairs, the Directorate General for International
Cooperation and Development, the concerned ministries,
the on-site embassies and DIPT. The projects were
systematically sent on to DIPT before being
redistributed for evaluation by the competent persons (8
days being allowed for evaluation). This "direct-flow"
system allowed for a rapid, efficient allocation of
resources. Out of a total of 200 project proposals,
nearly one hundred were selected by DIPT. Three to four
weeks were allowed for the projects' analysis and
revision. The NGOs interviewed seem to have then
waited between one and four months - a relatively
short amount of time - before receiving their funds.
As
regards programme monitoring, DIPT relied principally on
the embassies' Cooperation and Cultural Action Services
(SCACs) in the concerned countries. This monitoring
took several forms:
- Daily follow-up via the SCACs, which had to deal
with difficult working conditions with regard to
available personnel and logistics.
- Regular exchanges with the Fondation de France
and international institutions such as the United
Nations, which carry out their own follow-ups.
- On-site missions carried out by DIPT in order to
better understand the problems, the on-site
realities, etc.
DIPT was dissolved in July and replaced by CPT, an
ad-hoc commission which was itself dissolved in
2005. The monitoring of post-tsunami projects has
therefore fallen to the SCACs and the international
community.
Source: Directorate General for International Cooperation and Development
|
In addition, DIPT allowed for the French contribution to
the warning system currently under construction in the Indian
Ocean to be defined and financed. Following the two meetings
held by the Intergovernmental Oceanographic Commission to define
the Indian Ocean warning system in Paris in March 2005 and in
Mauritius in April 2005, the system's structure was finalized in
the form of a coordinated network of national centres, with
France committing to build such a centre in La Réunion.
At the behest of DIPT, this project's partners47(*)
met on several occasions to define the actions to be carried
out and the amount of necessary funding. The initial project was
ambitious, in that it called for setting up a national,
multi-risk (tsunami, cyclone, abnormal-wave) warning centre
capable of managing both local and far-off tsunami warnings.
Within this context, €1.59 million were allocated to finance the following priorities:
- Equipping the Météo France centre in La Réunion, to
render it operational for teletsunami warnings (€20,000). Météo
France is the only French body in this region to be on-duty 24
hours a day, 7 days a week; for this reason, it was chosen as
the Focal Point. It receives the messages issued by PTWC and
JMA and, if need be, alerts the Etat Major de Zone et de
Protection Civile de l'Océan Indien ("Zone Civil-Protection
Headquarters for the Indian Ocean"), as well as the sub-prefect
on duty. In the initial project, the Météo France centre was
meant to generate its own tsunami warnings via the installation
of one TREMORS system and working in close cooperation with
IPGP, which would have analyzed the seismic data and provided
its scientific expertise.
- Bringing up to standard the seismological stations of the
GEOSCOPE network and transmitting the data in real-time to
Djibouti, Canberra, Hyberabad, La Réunion, Kerguelen, Dumont
d'Urville and Île Amsterdam, as well as installing a new station
in Madagascar (€511,000).
- Bringing up to standard the French tide gauges in La
Réunion and Kerguelen, as well as installing two new tide gauges
in Mayotte and Madagascar (€91,000).
- The carrying out by CEA/DASE of a tsunami-risk study for
the coastal regions of Madagascar and Sri Lanka, as well as
certain small island states located in the region (€50,000).
- Re-editing the "Tsunami, the
Great Waves" brochure, initially produced for the Pacific,
adapting it to the needs of the Indian Ocean (€20,000).
- Météo France's equipping Madagascar, Kenya and Tanzania with meteorological systems48(*)
(€157,000), setting up a weather station in Madagascar
(€40,000), and carrying out a survey in Yemen, Somalia and
Djibouti to evaluate the needs of these countries with regard to
updating their telecommunication means linked to the Global
Telecommunication System (GTS) (€40,000).
The latter measures are part of a multi-risk approach.
Their immediate goal is to improve the performance of these
countries' weather services by providing them with communication
and weather-forecasting systems. However, insofar as these
weather-forecasting systems are linked to the global network of
the World Meteorological Organization, responsible for issuing
tsunami warnings, the weather services equipped with said
systems will be capable of receiving these warnings in real
time.
Likewise, the weather
station installed in Toamasina, the capital of Madagascar's
eastern province regularly touched by tropical cyclones, is also
meant to serve as a tsunami warning centre. This centre is
therefore equipped with a Retim-Transmet-Synergie system, a
meteorological observation station and a tide gauge.
In addition, €420,000 were directly allocated to
CEA/DASE for digitizing the data from the Indonesian analogue
stations, installing 3 TREMORS systems adapted to the Indonesian
stations, training the personnel of the regional warning
centres, updating a seismic station to broadband, and testing
the performance of the Indonesian network via simulations.
€24,000 were also allocated to LDG/Pamatai for training Thai personnel about the warning systems.
Finally, €50,000 were allocated to the French committee
of the IOC for the financing of missions carried out by French
experts in the Indian Ocean, training missions for local
technicians in La Réunion or metropolitan France, and helping
local scientists participate in scientific programmes.
b) The commitment of the Ministry of Ecology
In December 2004, Nelly Olin, then French minister of
ecology and sustainable development, presented during a Cabinet
meeting the main lines of the Programme National de Prévention du Risque Sismique ("National Seismic-Risk Prevention Programme").
Following the Sumatra tsunami, a fourth theme, dedicated to
tsunami-risk prevention, was added to this programme, after it
was observed that the French coasts were vulnerable to tsunamis
"in several locations, in particular along France's West Indian
and Mediterranean coasts".
Initiated in 2005 and placed under the direction of the
Pollution and Risk Prevention Department ("Pollution and Risk
Prevention Department"), this programme of action extends until
2011 and is structured around 3 main themes: evaluating the
hazard, setting up a warning system, and raising public
awareness.
The
Pollution and Risk Prevention Department has commissioned BRGM
to carry out two studies in order to better understand the
French coasts' vulnerability to tsunamis.
(1) The creation of a tsunami database
BRGM was commissioned to create a computerized database on tsunamis to have touched France's départements (in metropolitan France, Guadeloupe, Martinique and La Réunion49(*)).
This catalogue may be consulted over the Internet and
provides the following information for each tsunami:
- The date and time of the phenomenon;
- Its geographical location;
- The original cause of the phenomenon; BRGM established
8 categories: earthquakes, explosions, meteorites, landslides,
volcanic eruptions, meteorological events, and unknown events.
The meteorological criterium was chosen in order to distinguish
between "real" tsunamis and tidal waves provoked by sea surges
or cyclonal swells which are of meteorological origin; BRGM
thereby avoids giving the impression of having overlooked these
events;
- Its impact: the severity of damages is broken down into 5 categories;
- Its intensity, according to the international
Sieberg-Ambraseys Tsunami Intensity Scale which rates tsunami
intensity on a scale from 1 to 6 ("unknown" to "disastrous");
- The concerned basin (the Mediterranean, the Atlantic, etc.).
A "tsunami-observation window" allows users to indicate
where the tsunami's impact was observed and to describe its
dynamic effects (wave number and height, retreat distance and
height, inundation distance and height, run-up height).
Another window indicates the epicentral characteristics of
the earthquake that caused the tsunami. This information is
taken from databases on France's seismic history managed by
BRGM.
Finally, a
bibliographical window was included, specifying the type of
source used, its name, date of publication, title, author and
place of publication, as well as the page(s) referring to the
tsunami.
In late 2006, 21
events were integrated into the database. This catalogue is
meant to contribute to the evaluation of the frequency and
intensity of tsunamis on France's coasts.
(2) A study on the vulnerability of the French coasts
BRGM also carried out on behalf of the Pollution and Risk
Prevention Department a preliminary study on tsunamis in the
Mediterranean and West Indies (Martinique and Guadeloupe)
centred around three main themes:
- Identify the a priori most dangerous tsunami-generating zones for France's Mediterranean and West Indian coasts.
- Simulate extreme but possible events that could generate tsunamis.
- Identify France's most tsunami-vulnerable coasts.
Two tsunami-source types were chosen: earthquakes and landslides.
For the western Mediterranean,
59 seismic zones were identified for their supposedly
homogeneous tectonic deformation and seismic potential. Next, a
maximum earthquake50(*)
was chosen as a reference for each zone. Likewise, IFREMER was
charged with identifying underwater landslide zones on the
continental shelf and slope off the French Mediterranean coasts;
20 zones were eventually identified and characterized by their
maximum unstable volumes.
Based on seismic zonings and ground movements, 6 scenarios where chosen as a priori
having the greatest tsunami-generating potential and/or
representing the most likely sources of earthquakes or ground
movements. They include:
- 3 earthquake scenarios
· A 6.8 magnitude earthquake with and an epicentre situated some fifty kilometres off the coast of the French Riviera in the Liguria Sea.· A 6.7 magnitude earthquake centred in the Gulf of Lion, some one hundred kilometres from Perpignan.· A 7.8 magnitude earthquake situated 25 km north of the Algerian coast.
- 3 underwater ground-movement scenarios
· A landslide located some twenty kilometres off the northwestern coast of Corsica; the destabilized volume is estimated at 0.75 km3.· A landslide located some fifty kilometres off the coast of Perpignan, in the area of the Lacaze-Hérault underwater canyon, characterized by an unstable volume of 0.055 km3.· A landslide estimated at nearly twenty-five kilometres southeast of Nice, with an unstable volume of 1 km3.
Simulations of these 6 scenarios indicate:
Scenario
|
Magnitude or volume
|
Maximum onshore wave height
|
Time of arrival
|
French coast affected
(amplitude >0.5 m)
|
North Liguria Sea earthquake
|
M = 6.8
|
2 m in Antibes
|
10 to 15 mins.
|
St. Tropez to Nice
|
Continental-terrace earthquake north of Algeria
|
M = 7.8
|
4 m in St. Tropez, Cannes
3 m in La Ciotat, Nice, Villefranche
|
95 to 100 mins.
|
Marseille to Menton
|
Gulf of Lion earthquake
|
M = 6.7
|
0.6 m in Agde, Port-la-Nouvelle
|
60 to 80 mins.
|
Between Perpignan and Béziers
|
Continental-terrace landslide west of Corsica
|
V = 0.75 km3
|
5-6 m north of Porto
|
5 to 15 mins.
|
Southwestern half of the coast between Porto and Bastia
|
Lacaze-Hérault Canyon landslide
|
V = 0.055 km3
|
1.5 m in Perpignan
1 m in Frontignan and Beauduc (Capelude)
|
45 to 80 mins.
|
Perpignan to Beauduc
|
Nice-Vintimille continental-terrace landslide
|
V = 1 km3
|
4 m in Antibes
3 m in Nice
|
10 to 20 mins.
|
St. Tropez to Menton (all the way to San Remo in Italie)
|
The synthesis of these 6 scenarios results in a sectioning
of the French Mediterranean coast according to the estimated
level of vulnerability. This sectioning takes into account the
maximum estimated sea level near the coast and the a priori
possible run-up level, irrespective of the initial source of
origin (earthquake or landslide). This represents an initial
evaluation of the French coasts' exposure to tsunamis.
Considering the characteristics of the 6 catastrophic
scenarios chosen as benchmarks, as well as the results of
additional simulations that have been carried out, this
synthetic map probably indicates rather well the regional level
of tsunami exposure for this part of the French coast.
This preliminary regional evaluation relies on calculations
with a cartographic precision of up to around 1:100,000
(calculations based on grids with a spatial resolution of 83 m x
83 m).
Therefore, it
cannot be used for tsunami-risk planning at the local level (for
example, in the elaboration of risk-prevention plans). Indeed,
more precise studies remain essential for a detailed tsunami
mapping at the local level according to the height, depth and
duration of inundation, as well as the number of waves and the
speed of the currents.
Tsunami-exposure map for the coasts of the Languedoc-Roussillon and Provence-Alpes-Côte d'Azur regions
Source: BRGM
Tsunami-exposure map for the coasts of Corsica
Source: BRGM
As regards the French West Indies,
seismic zoning carried out in the area of the Caribbean
Plate identified 32 seismic zones characterized by a maximum
earthquake. Five seismic-source scenarios were chosen.
Furthermore, based on an analysis of our current understanding
of tsunami-generating landslides and volcanic
eruptions/collapses, 3 additional scenarios were chosen.
Therefore, a total of 8 catastrophic scenarios were chosen as references and modelled:
The 5 seismic scenarios were the following:
· A magnitude 7.5 earthquake centred around the system of normal faults of the Marie-Galante graben.· A magnitude 8.3 earthquake located in the Barbuda prism; in other words, in the subduction zone of the North American Plate sinking beneath the Caribbean Plate.· A magnitude 7.5earthquake generated by the normal fault along the Anegada graben.· A magnitude 7.6 earthquake generated by the left reverse fault of the Saint Lucia ridge.· A magnitude 7.1 earthquake centred in the Barbados accretionary prism, generated by the reverse parallel faults along the subduction zone of the South American Plate sinking beneath the Caribbean Plate.
3 volcanic, subaerial ground-movement scenarios were also chosen:
· The 2003 Soufrière-Hills (Montserrat) event, corresponding to the collapse of the volcanic dome. The volume of debris entering the sea is estimated at 16 million m3.· The 1902 Mount Pelée (Martinique) event, associated with the penetration into the sea of a lahar with a volume of around 5 million m3.· The Soufrière (Guadeloupe) paleo-event concerning the collapse of a slope of the Soufrière volcano around 3100 B.C., sending an estimated 70 million m3 of debris into the sea.
The following table presents the results of the 8 simulations:
Scenario
|
Magnitude or volume
|
Maximum onshore wave height
|
Time of arrival
|
French coast affected
(amplitude >0.5 m)
|
Marie-Galante graben earthquake
|
M = 7.5
|
>3,5 m in Sainte-Marie (Martinique)
|
10 to 15 mins.
|
Northeastern Martinique
Southern La Désirade
Southern Grande-Terre (Guadeloupe)
|
~ 5 m in La Désirade
|
13 to 15 mins.
| |||
~ 3 m in Sainte-Anne (Guadeloupe)
|
#177;15 mins.
| |||
Barbuda earthquake
|
M = 8.3
|
=8 m in Le Moule, Anse-Bertrand, Clugny (Guadeloupe)
|
20 to 40 mins.
|
The entire coast of Grande-Terre and the northern
coast of Basse-Terre (Guadeloupe)
Western La Désirade
Northeastern coasts of Martinique
|
6 m in Le Marigot (Martinique)
4 m in La Trinité (Martinique)
|
35 to 45 mins.
| |||
Anegada Passage earthquake
|
M = 7.5
|
>1 m in Deshaies (Guadeloupe)
|
60 mins.
|
Northwestern Basse-Terre (Guadeloupe)
|
Saint Lucia ridge earthquake
|
M = 7.6
|
~1 m in Grande-Terre, southeastern Basse Terre, and Marie-Galante
|
20 to 30 mins.
|
Southern and eastern coasts of Grande-Terre,
southeastern Basse Terre, Marie-Galante
|
>2 m in la Désirade
|
20 mins.
|
Southern coast of La Désirade
| ||
>3 m in Le Marigot and La Trinité (Martinique)
|
15 to 30 mins.
|
Eastern coast of Martinique
| ||
Barbados prism earthquake
|
M = 7.1
|
<0.5 in Le François
|
15 to 20 mins.
|
Southern coast of Martinique
|
2003 Soufrière-Hills event (Montserrat)
|
Landslide,
V = 0.016 km3
|
>0.5 m in Deshaies and Malendure
|
12 to 15 mins.
|
Northern and western coasts of Basse-Terre (Guadeloupe)
|
1902 Mount Pelée event (Martinique)
|
Lahars,
V = 0.005 km3
|
>3 m in Saint-Pierre
|
<2 mins.
|
Northwestern coast of Martinique
|
La Soufrière event (Guadeloupe)
|
Landslide,
V = 0.07 km3
|
>3 m in Trois Rivières and Basse-Terre
|
<5 mins.
|
Southern and western coasts of Basse-Terre, Les
Saintes, western coast of Marie-Galante
|
In the light of observations already made concerning the
tsunami-exposure maps for the Mediterranean, these results
demonstrate a high to very high level of tsunami vulnerability
for almost all of Grande-Terre (Guadeloupe), eastern Basse-Terre
(Guadeloupe), La Désirade, Les Saintes, Marie-Galante (except
for the southern coast) and the eastern coast of Martinique.
Tsunami-exposure map for the coasts of Martinique
Source: BRGM
Tsunami-exposure map for the Guadeloupe archipelago
Source: BRGM
(3) Setting up a warning system
In addition to a better understanding of this natural
hazard, the tsunami-risk prevention project plans on setting up
tsunami-detection and tsunami-warning systems for the Indian
Ocean, the Mediterranean and the West Indies.
The presentation document for the November 2005 "earthquake plan" points out that "in
accordance with France's position as presented during the Kobe
conference and before the Intergovernmental Oceanographic
Commission, it has been decided to create a national, multi-risk
prevention centre in La Réunion".
Likewise, this document states that "the
Mediterranean and Caribbean are particularly prone to
tsunami-generating earthquakes [...]. In addition to bilateral
partnerships, France will propose - along with the concerned
European countries (in particular, Italy for the Mediterranean
and the United Kingdom and the Netherlands for the West Indies)
and in cooperation with the other countries ringing these
basins - European-level initiatives for tsunami detection and
the transmission of warnings."
Following the creation of intergovernmental coordination
groups in the Indian Ocean, the Mediterranean and the
Caribbean, a national coordination group was set up to organize
regular meetings in the various basins and finalize the French
position. Co-directed by the Pollution and Risk Prevention
Department and the DDSC ("Defense and Civil Protection
Department"), this informal body gathers together all the French
players more or less directly involved in the setting up of a
warning system, including both scientific and technical
organizations (CEA, IFREMER, IPGP, Météo France, BRGM, SHOM,
CNRS, IRD) and ministries (the Ministry of Ecology and
Sustainable Development, the Ministry of the Interior, Overseas
Territories and Local Governments, the Ministry of Foreign
Affairs).
(4) Educating the public and raising awareness
Finally, the objective of the tsunami-risk prevention
project is to raise public awareness in the most vulnerable
zones.
Particular attention
has been given to raising student awareness and training
teachers. Certain actions are already under way; for instance,
primary and secondary-school programmes already deal with major
natural risks. What's more, the tsunami of 26 December 2004 gave
rise to numerous school initiatives, particularly in the
West Indies, La Réunion and the Mediterranean, which are
largely based on already-existing projects, such as the "Sismo
des écoles" (seismometer at school) project carried out in the
Académie de Nice and the Académie des Antilles.
From "Sismo des écoles" to "Sismos à l'école"
The principle of the "Sismos à l'école"
("Seismometers at School") project is to create a
network of schools equipped with educational
seismometers. A seismic sensor is installed in each
school by students from 13 to 18 years of age. The
sensors' seismic data is fed into an on-line database;
this veritable seismic resource centre serves as the
starting point for various educational and scientific
activities using new information and communication
technologies.
Considering the project's orientation (emphasizing
new communication technologies), its educational
aspect (raising awareness of seismic risk), its
scientific content (instrumentation, geophysics, earth
sciences) and its importance at the both the regional
and national levels (creating a network of schools), it
offers teachers numerous educational paths to explore.
The project's objectives are the following:
- Favour the development of the hard and
technological sciences at the secondary-school level,
via a project centred around the measuring of an
environmental parameter.
- Raise children's awareness of natural risks,
thereby contributing to the accountability of these
future citizens.
- Encourage students to become "ambassadors" within
their communities for natural-disaster prevention.
Launched in
1996 at the Centre International de Valbonne, the
"Sismo des Ecoles" programme rapidly spread within the
Alpes-Maritimes département with the support of
the Académie de Nice, the departmental council
and the Géosciences Azur laboratory.
Today, the national network consists of a total of
20 schools: 13 in metropolitan France, 3 in the
DOM-TOM and 4 in French secondary schools abroad.
|
In addition, specific teacher-training initiatives for
academies concerned by the tsunami risk are planned, as is the
development of educational tools dedicated to this theme.
Furthermore, raising the public's awareness and ensuring
its appropriation of the information necessitates identifying
the different categories of the exposed populations (residents,
tourists, professional groups, etc.), adapting the messages, and
identifying the most suitable transmission tools.
c) At the local level, a real raising of public awareness of the tsunami risks
During this study, your rapporteur observed that the level
of awareness among politicians with regard to natural risks
increased in proportion to their proximity to the population.
Despite all the noise, tsunami-risk prevention hardly seems to
be a national priority, as evidenced by the past two years of
prevarication in attempting to finalize the official French
position. However, this subject has generated real political
involvement at the local level, essentially in response to the
high level of public interest.
The policies pursued by the departmental councils of the
Alpes-Maritimes and Martinique illustrate the desire of the
local governments to protect against natural risks.
The Alpes-Maritimes département
is threatened by most natural risks, from forest fires to
avalanches, to landslides, droughts, earthquakes, tsunamis and
inundations. At the behest of its president, Christian
Estrosi, the departmental council launched a programme for
natural-risk prevention, with an emphasis on geophysical risks
and the aim of creating a departmental competitiveness cluster,
transforming the area's dangerous geological situation into a
motor of economic development.
In this context, an agreement was signed in 2003 between the
departmental council of the Alpes-Maritimes and the "University
Think Tank for an Environmental Risk Agency" Scientific
Interest Group (or GIS CURARE)51(*).
This body's mission is to demonstrate the pertinence of
gathering together the scientific and technical skills in the
environmental and natural-risk domain in order to better analyze
and understand the environmental phenomena and meet both public
demand and government orders. This project, which comes to an
end in December 2007, should facilitate the creation of a
natural-risk competitiveness cluster for first the
Alpes-Maritimes and then the entire Provence-Alpes-Côte d'Azur
region (PACA); it also prefigures the future environmental-risk
agency, to be created in 2008 and which is meant to be solicited
by those companies having to undertake assessments in this
region and, more generally, within the entire Arco Latino.
Indeed, the Languedoc-Roussillon region is also concerned by the
creation of this agency, and its relations already
developed with the Italian and Spanish environmental-risk
agencies hint at the rapid development of a recognized expertise
in geological risks for the Mediterranean area.
Since its launch, the GIS CURARE has centred its attention
on three sets of issues, including that of tsunamis and
landslides in the sea or ocean.52(*)
The objective was to precisely locate the active underwater
faults and zones prone to landslides, in order to quantify the
likely landslide volumes and model the importance of the
resulting local tsunamis. These studies, half funded by the
departmental council, have therefore improved our
understanding of this hazard in a zone particularly prone to
local tsunamis generated by landslides.
Furthermore, following the Sumatra tsunami, the president
of the Alpes-Maritimes departmental council requested the GIS
CURARE to organize for the end of February 2005 an
international conference on "Creating a tsunami warning network
for the western Mediterranean". During this conference,
Christian Estrosi emphasized the need to set up a Mediterranean
warning system. Following the conference and due to the
involvement of the GIS CURARE in actions organized by the French
delegation in preparation for the ICG/NEAMTWS meetings, the
director of the GIS CURARE was chosen as the national contact
for the Mediterranean/Northeast Atlantic zone by the president
of the National Committee for the IOC.
Finally, the organization of the second session of the
ICG/NEAMTWS by France in May 2006 demonstrated the political
will of this country to rapidly succeed in setting up a tsunami
warning system for the Mediterranean. In addition, this meeting
was held in Nice because of the strong commitment of the
departmental council's president - at the time Minister for
Regional Development - in favour of such a system.
During his visit to Martinique, your rapporteur observed that the departmental council of this département, presided over by our colleague Claude Lise, was also very active in natural-risk prevention.
Firstly, the departmental council supported the creation of
Martinique's geographical information system: a
geographical database consisting of digitized maps, scanned
photos, all types of measurement taken in real time, land
surveys, socio-economic and town-planning information, etc. and
meant to be used as a tool in risk management and regional
development. This database can thus be used to map the
submersion risk in the event of a tsunami for the coastline of a
specific district by superimposing its inundation and cadastral
maps.53(*)
Secondly, Martinique's departmental council launched a
public-awareness campaign on natural risks via an innovative
educational tool: the "major-risk prevention caravan". This
caravan, made up of three 25 m² tents, houses exhibitions,
educational films on major risks, a multimedia quiz and a
multimedia game for children aged 6 to 12. As regards the
information provided on tsunamis, one of the films presents the
earthquake of 26 December 2004 and the tsunami which followed,
using first-hand accounts and scientific documents. Visitors can
also watch a computer model developed by CEA.
Finally, the departmental council is setting up an
extensive network of measuring devices (wave recorders, weather
stations, accelerometers) in order to better understand and
monitor natural risks. It has also set up a tide gauge at Le
Prêcheur to be used for tsunami monitoring, although its
principal mission is to study sea surges during storm surges.
The council also plans on installing a second tide gauge on the
Atlantic coast in the district of Le François.
d) The launch of a warning system in New Caledonia and in Wallis and Futuna
While French Polynesia already benefits from an effective
warning system, the system for New Caledonia and Wallis and
Futuna is still in its early stages. Due to these territories'
isolation and low population density, their tsunami-based
observations remain very incomplete. However, several tsunamis
were recorded during the 19th and 20th centuries, generated by earthquakes near the Solomon, Vanuatu and Loyalty Islands.
Recently two events reminded us of these territories' tsunami vulnerability.
On 3 May 2006, following a magnitude 7.8 earthquake with in
the Tonga Islands, PTWC issued a warning for the islands of
Tonga, Niue, Samoa, Wallis and Futuna and Fiji.
On 1 April 2007, a magnitude 8.1 earthquake in the
Solomon Islands subduction zone generated a devastating local
tsunami. In New Caledonia, the authorities were alerted by PTWC
and the High State Authority decided to evacuate (as a
precaution) the Loyalty Islands and the eastern coastal
districts.
The Sumatra
tsunami, combined with both the arrival in New Caledonia of the
former High Commissioner for French Polynesia (who had
instigated the installation of sirens on this territory) and the
raised awareness of the Ministry of Overseas Territories (which
has since become the Junior Minister's Office for the Overseas
Territories) and the tsunami-vulnerable districts in New
Caledonia and Wallis and Futuna, provided the impetus for
setting up a warning system in these two territories.
In May 2007, the Junior Minister's Office for the
Overseas Territories spent €22,000 to provide itself with a
central warning station. In addition, New Caledonia is in the
process of acquiring sirens for the districts of Ouvéa
(3 sirens), Lifou (8 sirens) and Maré (3 sirens). These sirens
are funded primarily by the inter-district equalization fund
and, to a lesser extent, by the global allocation of equipment.
The Junior Minister's Office for the Overseas Territories has
also provided money for the installation of sirens in
Wallis and Futuna.
***
Even so, overall, nearly three years after the Sumatra
tsunami, France's initial interest has waned, due to the lack of
a strategic vision and insufficient funding.
B. A MOVEMENT THAT IS RUNNING OUT OF STEAM, DUE TO THE LACK OF A STRATEGIC VISION AND INSUFFICIENT FUNDING
The difference is striking between the ambitions put
forward by the French government in 2005 with regard to setting
warning systems in the various basins and the meager results
that have been achieved two years later.
1. The observed hurdles
In reality, France's initial commitment has given way to a
wait-and-see policy revealing various internal blockages.
a) In the Indian Ocean
The Indian Ocean is the only basin for which the French
contribution has been the subject of a detailed action plan and
which has benefited from a subsidy of over €2 million.54(*)
Nevertheless, two years after the programme's launch, the
results do not meet the project's initial expectations.
The initial plan called for setting up a national tsunami
warning centre capable of monitoring both regional and local
tsunamis. Because of its volcanic and seismic experience and
skills, IPGP was meant to collaborate closely with the Météo
France centre to ensure the tsunami warnings. However, this
ambitious project quickly encountered funding difficulties.
Indeed, the subvention allocated to the French contribution to
the Indian Ocean warning system only includes equipment
funding. However, the warning system that was initially proposed
required that both Météo France and IPGP remain on-call 24
hours a day, 7 days a week, which its operating budget simply
did not cover.
In addition,
Météo France questioned the pertinence of extending the
national warning centre's capacities to the issuance of local
tsunami warnings, estimating that the appropriateness of such an
action should first be studied. However, neither CEA nor IPGP
was assigned with carrying out such a study and it seems that
the project has been abandoned.
As is also the case in the West Indies, Météo France
currently receives the warning messages issued by PTWC and JMA,
which it then forwards to the prefect. As a result, the €305,000
set aside for developing the national warning centre's
capacities in order to render it operational in the event of a
local tsunami have yet to be spent (although their reallocation
has not yet been discussed).
Furthermore, the French contribution is far behind schedule
in up-to-dating and installing the tide gauges entrusted to
SHOM. In a document prepared by the National Committee of the
IOC on the funding of the French contribution to the Indian
Ocean Tsunami Warning System (IOTWS), dated 29 June 2005, this
action is qualified as being "one of the IOC's most important, in terms of both its symbolic importance and the credibility of the IOTWS."
However, only a single real-time tide gauge has so far been
installed (La Réunion, October 2007), even though there is
available funding.
Neither
the real-time tide gauge planned for Mayotte, nor that planned
for Madagascar has been installed. According to the information
provided by SHOM to your rapporteur, the Mayotte tide gauge
should be up and running in 2008. However, no date has been
fixed for the Madagascar tide gauge, because it has not been
included among SHOM's official priorities.
As regards the Kerguelen tide gauge managed by LEGOS, it
has been brought updated along with the GEOSCOPE seismic
station managed by the EOST in Strasbourg.
The updating of the GEOSCOPE network's seismic stations is
also behind schedule, because only 2 out of the 5 initially
planned stations55(*)
transmit their data in real-time. IPGP has not yet installed a
VSAT antenna on the Djibouti station, in order to allow it to
receive data in real-time. According to the information
obtained by your rapporteur, IPGP has also run up against
India's refusal to transmit the data from its Hyderabad seismic
station in real-time. Therefore, the plan to update this station
has been abandoned, so as to instead install a station on
Rodriguez Island. It has therefore been necessary to increase
the funds allocated to IPGP to cover the expenses of this new
mission. The Madagascar seismic station should be installed in
March 2008; the site is ready and the material and equipment
have been sent, but work cannot begin before the end of the
rainy season. Less progress has been made in setting up the
Rodriguez seismic station.
During a hearing, IPGP's director, Vincent Courtillot,
estimated that updating the 3 older stations and installing the 2
new stations necessitated hiring the services of two engineers
over a three-year period. He regretted that IPGP had been
obligated to cover these expenses, for want of the planned
operational subsidy. He also expressed his anxiety regarding the
budgetary costs entailed by financing the VSAT transmissions.
An assessment of the funds
allocation by the Ministry of Foreign Affairs for the creation
of a national tsunami warning system leads us to the following
conclusions:
- Of the €1.5
million allocated, €305,000 have yet to be spent, for want of a
preliminary study on La Réunion's vulnerability to local
tsunamis.
- Of the €1.1
million that have actually been spent, half were allocated to
Météo France Internationale in order to improve the
weather-forecasting systems of the neighbouring countries.
Although this programme will enable these countries to also
receive the warning messages, your rapporteur believes that
these measures are only indirectly related to the setting up of a
tsunami warning system. Considering the scarcity of funds
so far allocated by France for tsunami prevention, this money
could have been spent more wisely. Finally, although Météo
France's role in the region - in particular, within the
framework of the cyclone-warning system - has been strengthened,
neither the seismic system nor the tide gauge system is
completely operational, even though both constitute pillars of
the tsunami warning system.
b) In the Caribbean
In the Caribbean, the commitment of France to set up a
warning system runs up against numerous obstacles: not only has
the public only recently been made aware of the tsunami risk,
but the existing measuring devices are not suited to the setting
up of an effective tsunami warning system. In addition, due to
the lack of both political will at the national level and a
specific budget to fund their actions, those scientific
organizations representing France in the ICG/Caribbean-TWS enjoy
little room for manoeuvre.
The civil protection authorities have only very recently taken
into consideration the tsunami risk. Although the tsunami risk
is certainly familiar, up until now, it has not been considered a
priority due to the difficulties already encountered in dealing
with those risks that are most present in the collective
conscience (cyclones, earthquakes, volcanic eruptions).
During your rapporteur's visit to Martinique, he was struck by the poor preparation of this département with regard to natural geophysical risks.56(*)
Indeed, even though Martinique is exposed to a high
earthquake risk, most buildings do not meet the seismic-safety
standards, while the population remains unreceptive to
information and public-awareness campaigns. For instance, your
rapporteur learned that in the event of an earthquake comparable
in magnitude to that of 183957(*),
the prefecture, most fire stations and the island's hospitals
would be the first buildings destroyed, thereby seriously
hampering the subsequent relief effort. Likewise, the volcanic
and seismic observatories in Martinique and Guadeloupe do not
meet the safety standards.
France's active participation in the ICG/Caribbean-TWS is
also hindered by the fact that the measuring devices are not
suited to the technical demands of a tsunami warning system.
Martinique is equipped with
two tide gauges: one in Fort-de-France belonging to SHOM and one
installed in Le Prêcheur by the departmental council, which is
also expected to install a third tide gauge on the Atlantic
coast.
In Guadeloupe,
there are 5 tide gauges, one of which belongs to SHOM, with the
remaining 4 being managed by the OVSG ("Volcanic and
Seismological Observatory of Guadeloupe").58(*) The regional council should fund a sixth tide gauge planned for Les Saintes.
Nevertheless, none of the tide gauges transmit their data
in real-time and neither SHOM nor IPGP has the necessary
funds to bring them updated and cover the cost of transmissions.
What's more, SHOM has no local antenna in the West Indies. As a
result, no SHOM specialist attends meetings held by the working
subgroup on devices for measuring sea level within the
framework of the ICG/Caribbean-TWS.
IPGP, via its two observatories, is responsible for
monitoring the seismicity of the French West Indies. However,
its seismic network needs to be modernized, particularly with
regard to data transmission which is currently carried out by
radio and therefore incompatible with the demands of an
effective tsunami warning system.
The director of the OVSM ("Volcanic and Seismological
Observatory of Martinique") has been chosen as the National
Contact for the ICG/Caribbean-TWS, because of the fundamental
role that the seismic network is supposed to play in the tsunami
warning system. Nevertheless, since the OVSM is not on-call 24
hours a day, 7 days a week, the Météo France centre in
Martinique has been put in charge of receiving the warning
messages issued by PTWC and then transmitting them to the
prefect.
During your
rapporteur's visit to Martinique to evaluate France's
involvement in the setting up of a tsunami warning system for
the Caribbean, he was shocked to see France discard its
international responsibilities by assigning them to scientific
organizations that, for want of any precise ministerial orders,
not only have difficulty in acting, but also cannot legitimately
represent France.
Today,
the silence of the French government forces IPGP to alone
define, via the OVSM, the orientation of France's contribution
to the warning system. Considering the lack of political support
and the limited means at its disposal, the OVSM, expecting the
University of Puerto Rico to eventually be chosen as the
regional warning centre, has chosen to limit France's
involvement to the sharing of tide gauge and seismological data
with the other ICG/Caribbean-TWS member states.
To this end, the OVSM has mobilized the GEOSCOPE network
and built bridges with SHOM. In addition, OVSM's actions have
allowed for a real raising of awareness among public authorities
and local players with regard to the tsunami risk, which is now
included in the "West Indies-Guiana Risk Club" working group,
which gathers together the various partners involved in the
monitoring and management of natural risks.
Nevertheless, your rapporteur considers that only the
government can legitimately decide French policy. In addition,
only the French government has (or should have) a global view of
the various negotiations currently under way in all four
basins, allowing it to make the most pertinent decisions. Also,
your rapporteur would like to point out that France could become
the regional tsunami warning centre in the Caribbean, if CEA
were to assume this responsibility in the Mediterranean.
During his visit to Martinique, your rapporteur learned
that the then Minister of the Overseas Territories had
instructed the prefect to set up a specialized emergency plan
modeled after the French Polynesian plan. Your rapporteur
recognizes that a plan for the organization of emergency prior
to a warning being given is, in fact, indispensable for ensuring
the population's protection. However, this request cannot be
satisfied without first obtaining the necessary information for
the elaboration of such a plan.
Indeed, the organization of emergency assistance measures
will vary according to the time delay available (before the
arrival of the tsunami) to the civil-protection services;
establishing this reaction time requires an excellent
understanding of those zones liable to provoke a tsunami.
In addition, the measures to be carried out depend on the
tsunami-vulnerability of the concerned coasts. Your
rapporteur would like to point out that BRGM has been assigned
with carrying out just such a study by the Ministry of Ecology.
However, due to the lack of a precise bathymetry near the
coasts, the results are not sufficiently reliable to be used for
the elaboration of a specialized emergency plan.
c) In the Mediterranean
In the Mediterranean, France is exposed to both regional
tsunamis from Algeria and local tsunamis provoked by
earthquakes in the Liguria Sea or a landslide in the zone
between Nice and Vintimille. Having to deal with short reaction
times, the national tsunami warning centre, in order to be
effective, is best managed by a scientific body capable of
refining a regional warning message59(*)
in less than 15 minutes, 24 hours a day, 7 days a week, and
then transmitting it to the COGIC ("Operational Interministerial
Crisis Management Centre") and, if need be, the regional and
local civil-protection authorities.
CEA is best suited to taking charge of this mission,
because it is already responsible for notifying the French
authorities in the event of an earthquake with a magnitude of
greater than 4 on national territory, it hosts the
European-Mediterranean Seismological Centre, and it serves as a
benchmark for tsunami simulations and evaluation and the
management of tsunami warnings in French Polynesia. As France is
vulnerable to tsunamis in several basins, we can expect the
future national warning centre to manage warnings for the
Mediterranean, the Caribbean60(*) and the Indian Ocean.
Furthermore, because it must receive all the data from the
various seismic and sea-level measurement stations (tide
gauges and tsunamimeters), it could also act as the regional
tsunami warning centre, although the national authorities would
remain ultimately responsible for the issuance of tsunami
warnings.
During the
international conference held in Nice in February 2005, the then
Minister of Ecology, Serge Lepeltier, stated that the
European-Mediterranean Seismological Centre represented "a
structure predisposed to playing a major role in the elaboration
and implementation of a warning system in the Mediterranean
basin."
In April 2006,
the then Minister of the Interior, Nicolas Sarkozy, asked the
general director of CEA if this body could act as the regional
tsunami warning centre for the Mediterranean. CEA replied in the
affirmative61(*), so long as it was provided with the necessary human and financial means.
Concretely, CEA's proposal referred to two types of expenditure:
- The initial funding costs (€2.7 million for CEA). For
the most part, this money covers: the adaptation of several CEA
seismic stations; the acquisition of a GTS-reception system;
the development of high-speed seismic computer programs (2-6
mins.); the integration of data-reception and GTS-message
programs, as well as programs for the real-time visualization of
sea-level data; the development of programs for gathering data
from non-CEA seismic stations. This sum does not cover the
seismic equipment of those stations set up outside France, with
the exception of the VSAT antennas, updating the Madeira
station (in partnership with the University of Lisbon), and
setting up a seismic station in the Azores. The costs linked to
the installation of 20 tide gauges and 6 tsunamimeters are
estimated at €2.4 million.62(*)
- The operating costs (€3.5 million). A large part of
this sum covers supplementary personnel expenditures linked to
the setting up of a team on duty 24 hours a day. This amount
also covers: the cost of VSAT transmissions and the maintenance
of the related equipment; the maintenance and updating of the
means for processing and issuing tsunami warnings; database
storage; the updating of scenarii modelling; participating in
the meetings organized by the ICG/NEAMTWS. The cost of
maintaining the tide gauges and tsunamimeters is estimated at
€310,000 per year.
However, since CEA's technical proposal was officially submitted to the concerned ministries63(*)
in November 2006, no concrete negotiation has been opened.
While it is true that several meetings have been held at the
technical-service level, they were unable to succeed. Indeed,
up until the Lisbon session of 20-23 November 2007, no political
decision had been made concerning the nature and funding of the
French contribution to the tsunami warning system, leaving such
fundamental questions as the following unanswered:
- Is France - via CEA/EMSC - ready to act as a regional
tsunami warning centre for the Mediterranean and, if so, for
which geographic zone64(*)?
- If France does not want to act as a regional warning
centre, will it nevertheless set up a national tsunami warning
centre and, if so, what will be its structure?
- To what extent does France want to participate in
updating its territory's existing tide gauges and installing
tide gauges and tsunamimeters off the coast of Algeria to
protect its coasts?
However, the uncertainties weighing on France's real
contribution to the tsunami warning system for the Mediterranean
have placed the French delegation in a particularly
uncomfortable position: for lack of any specific ministerial
directive and in the absence of funding dedicated to
tsunami-risk prevention, the French delegation is unable to make
any proposals which would commit France financially.
The representatives of the various administrations and
bodies that make up the French delegation have therefore reached
the limits of their competences: they were able to correctly
complete their missions as long as the ICG/NEAMTWS meetings
consisted of, on the one hand, listing the scientific work
carried out with regard to tsunami evaluation and, on the other,
quantitatively and qualitatively assessing each country's
seismic and tide gauge measuring devices.
However, since the Bonn session, the project for a tsunami
warning system for the Mediterranean has entered the
implementation phase, with the member states now spending each
new meeting presenting the concrete contributions they have
made. For example, in Bonn, Italy announced that it would ensure
the permanent collection and processing of seismic data from
the seas surrounding Europe. The tsunami information bulletins
would be issued by the Istituto Nazionale di Geofisica e
Vulcanologia (INGV).
On the
other hand, the French scientific bodies refuse to make any
commitments in the absence of any official directive or
financial commitment on the part of their government. The
question of updating France's tide gauges serves as a good
example. SHOM manages 23 tide gauges in metropolitan France,
including 5 in the Mediterranea sea; however, only Le Conquet
tide gauge transmits its data in real-time. Insofar as updating
its tide gauges to function in real-time does not constitute a
priority for this body and no additional means have been
accorded to SHOM to speed up the updating of its tide gauges and
ensure that they remain operational, most data from France's
tide gauges will not be useable in 2010, at which time the
Mediterranean tsunami warning system is expected to be
operational.
The fact that
since the resignation last June of the former director of the
Géoscience-Azur laboratory as acting National Contact, France
has been unable to find a replacement testifies to the current
log jam: unofficially, the members of the French delegation are
unanimous in confirming that this mission should fall to CEA.
Nevertheless, this body refuses to assume financial
responsibility for this task and is therefore awaiting a
commitment on the part of the French government to fund this
mission.
Therefore, your
rapporteur would like to point out that up until the Lisbon
session, France was unable to not only specify its role within
the future tsunami warning system in the Mediterranean, but also
to designate its Focal Point (responsible for transmitting
warning messages to the civil-protection services) and National
Contact (responsible for representing France at meetings of the
ICG/NEAMTWS). In addition, France's contribution to
bringing the sea-level measurement devices up-to-date is
hampered by a lack of funding.
Your
rapporteur is nevertheless pleased with the evolution of the
French position during the Lisbon session, which was held only
two weeks prior to the adoption of this study by the
Parliamentary Office for the Evaluation of Scientific and
Technological Choices.
Before the fourth meeting of the ICG/NEAMTWS (21 to 23
November 2007), it seemed that France was once again off to a
poor start, since only one day before the start of this session,
the French delegation still had not received any directive from
the government and was therefore preparing to maintain a low
profile.
However, the head
of the delegation finally received "certain indications" from
the Prime Minister's departmental staff conveying a favourable
evolution of French policy and the government's commitment to
the setting up of a tsunami warning system.
Concretely, the French delegation announced France's
interest in hosting a regional tsunami warning centre for the
western Mediterranean and northeast Atlantic zones, in
cooperation with the regional centre for the eastern
Mediterranean.
It was therefore decided to create a task team65(*)
to meet in January in order to determine the structure of the
Mediterranean and northeast Atlantic warning systems, as well as
the project's partners, implementation schedule and necessary
budget and sources of funding.
"Certain indications"
«France
would like to point out that during the Kobe Conference
it committed itself to participating in the design and
implementation of an oceanic, multi-risk monitoring and
warning system within the framework of an international
effort under the direction of the IOC.
Considering
the extent of its coastline, present in all of the
planet's principal sea and ocean basins, risk prevention
via the monitoring of natural hazards (especially
marine events), whether of geophysical or meteorological
origin, is today a major concern of France. Indeed, the
perspectives announced by the scientific community with
regard to global warming - resulting, in particular, in
rising sea levels and more intense meteorological
phenomena - necessitate an immediate and real
mobilization, as well as a concerted effort, on the
part of the concerned countries in the various basins.
Therefore,
France considers that it is today important to begin an
incremental process in line with the international
calendar proposed by the IOC, which is based on what is
currently available (or will be within 3 to 4 years) and
which deals, in particular, with coastal inundationing
caused by oceanic phenomena of distant origin.
In
particular, with regard to the Mediterranean and
northeast Atlantic basins, France does not underestimate
the decisive role it must play, considering, firstly,
the extent and diversity of its coastline and the
variety of natural hazards to which it is exposed and,
secondly, the collaborative agreements (in particular,
the emergency-assistance agreements) which it has
passed with several other coastal countries. In
addition, France is competent in the domains of
seismology, geophysics and meteorology.
France
cannot act alone, but must work in partnership with
other countries sharing this same set of problems.
Indeed, this is a European-Mediterranean project that,
due to its complexity and costs, requires a sharing of
strengths and means in which the European Union
must also assume its full responsibility - in
particular, with regard to its programmes relative to
the environment and security.
It
is in this context that France manifests its interest
to host a regional tsunami monitoring centre -
specifically, for the western Mediterranean and
northeastern Atlantic zone - as its contribution to
NEAMTWS. This centre would work in close partnership
with the eastern Mediterranean centre. Remaining in
permanent contact, these two centres would be able to
replace each other if needed; they would issue their
bulletins directly to the national authorities in charge
of spreading the alert.
For
this collaborative effort to succeed and in order to
set up a global European-Mediterranean project by
mid-2008, France proposes that a task team be formed
starting in January (the exact date to be fixed in
Lisbon). This team would add a political section to the
project's scientific and technical dimension. Its
mission would be:
-
to define the structure, means and partners of the
monitoring centre for the western Mediterranean and
northeast Atlantic;
- to establish a calendar for the centre's creation and activation;
-
to assess the costs of the different stages of the
project and to examine the conceivable contributions;
-
to consider the possible and ultimately probable
contributions of the observation and monitoring systems
that already exist or are being developed.
This
task team would present the results of its study during
the next meeting of the ICG/NEAMTWS, by identifying, in
particular, the initial funding necessary for the
creation of a monitoring and warning "kernel" to address
the European-Mediterranean and international concerns
with regard to coastal risks of oceanic
origin.
Finally,
France suggests that this task team be led by CEA,
considering this body's experience in the Pacific Ocean
and the fact that it hosts the European-Mediterranean
Seismological Centre.
|
d) In the Pacific
As has already been pointed out, the recognition of the
vulnerability of New Caledonia and Wallis and Futuna has led
France and the local authorities to begin installing sirens in
these territories. However, in order for this measure to be
effective, a reliable warning system must also be set up that
allows sufficient time to the local authorities to activate the
sirens.
Currently, there
exists only one tide gauge in New Caledonia (Nouméa) and four
tide gauges (Central Vanuatu, Fiji, Northern Samoa and Central
Tonga) which are poorly positioned to effectively protect
France's territories in the southwest Pacific.
A study - funded, in part, by the Junior Minister's Office
for the Overseas Territories - was carried out last July, in
order to evaluate the needs in tide gauges and tsunamimeters.
The study's conclusions were as follows:
6 seismic zones were distinguished as being capable of
generating tsunamis in New Caledonia and in Wallis and Futuna:
the Solomon Islands, the Vanuatu Islands, the Loyalty Islands,
the Fiji Islands, the Tonga Islands and the Kermadec Islands
(see map below).
The tsunami-generating seismic zones threatening New Caledonia and Wallis and Futuna
1
3
4
6
2
5
West of Solomon Islands
West and south of Solomon Islands and north of Vanuatu Islands
South of Vanuatu Islands
South of Fiji Islands
North of Tongan archipelago
South of Tongan archipelago/Kermadec Islands
 |
Source: CEA/DASE
- To the west and south of the Solomon Islands, as well as
north of the Vanuatu Islands (zone 2 on the map): 4
sea-level measuring stations are necessary to detect tsunamis
generated in this region: 3 tide gauges - one northwest of
Esperitu Santo (an island in the Vanuatu archipelago), one
southwest of Santa Catalina and one east of Renell Island (both
located in the Solomon Islands) - and a tsunamimeter to the
north, between the Solomon Islands and New Caledonia (that the
Australians are planning on installing).
- South of the Vanuatu Islands and in the area of the
Loyalty Islands (zone 3): an earthquake with a magnitude of
greater than 7.1 in this zone would generate a local tsunami
with a very short reaction time for the Loyalty Islands.66(*)
However, the installation of a tide gauge in both Lifou and
Maré would allow for a warning to be confirmed 20 minutes before
the arrival of the first wave on New Caledonia and 2 ½ hours
before the arrival of the tsunami in Futuna.
- North of the Tongan archipelago67(*)
(zone 5): two tide gauges (one in Wallis and one in Futuna), so
that if one of the two islands is hit by a tsunami, the other
island can be notified of its approach (the maximum
reaction time is estimated at 20 minutes). These two tide gauges
would also be used to confirm a warning 2 ½ hours before the
arrival of a tsunami from the Loyalty Islands or New Caledonia.
In addition, 2 other sea-level measuring stations are necessary
to confirm as quickly as possible (10 to 30 minutes earlier) the
tsunamis generated in this region: one tide gauge installed
south of the Samoa Islands and one at the far northern end of
the Tonga Islands. A tsunamimeter east of the Tongan archipelago
(that the Americans are expected to install) will later
allow for the tsunami's magnitude to be confirmed.
With regard to zone 1 (west of the Solomon Islands) and
zone 6 (south of the Tonga Islands/in the area of the Kermadec
Islands), these zones will be monitored by the tide gauge
planned to be installed east of Renell Island, as well as by the
measuring devices that Australia is expected to install.68(*)
To sum up, the sea-level monitoring system for this region must include:
- 7 tide gauges in the French overseas territories (3 in
New Caledonia, 1 in Lifou, 1 in Maré, 1 in Wallis and 1 in
Futuna), with the Wallis and Futuna stations contributing to the
warning system covering New Caledonia and the Loyalty Islands
for tsunamis generated in the Tongan archipelago, and with the
Loyalty Island and New Caledonia stations issuing regional
warnings for tsunamis generated in the Vanuatu Islands and
Loyalty Islands.
- 6
sea-level measuring stations installed off other islands, to
detect as soon as possible tsunamis moving towards the French
territories (2 in the Solomon Islands, 2 in the Vanuatu Islands,
1 in the Samoa Islands and 1 in the Tonga Islands).
- 1 tsunamimeter installed by the Australians north of New Caledonia.
To complete the system, two tide gauges should subsequently
be installed in Ouvéa and Ouinné, as well as a tsunamimeter
in the Tonga Islands and Fiji Islands.
As has already been pointed out, the Junior Minister's
Office for the Overseas Territories is well aware of the stakes
and is helping to fund the setting up of a warning system in the
southwest Pacific. Nevertheless, its finances are insufficient.
Political arbitration is therefore essential to finalize the
structure of the warning system for New Caledonia and Wallis and
Futuna and establish a suitable budget.
2. The reasons for these blocks
The observed obstacles blocking France's participation in
the setting up of a tsunami warning system for the various
basins all share the same origin: due to a lack of political
will, the French contribution is the subject of no global action
plan and depends upon the good will of the various engineering
departments, ministries and scientific bodies. As the latter do
not benefit from sufficient funding due to the absence of any
specific budget dedicated to setting up tsunami warning systems,
progress has been very slow.
a) The absence of a global vision
France is the only country to belong to the four
intergovernmental coordination groups for setting up a tsunami
warning system. In addition, the design and implementation of a
monitoring system necessitates a large number of partners, at
both the ministerial level and the public-service,
scientific-body and local-government level.
Unfortunately, ever since France agreed in 2005 to
contribute to the tsunami warning systems, no government has
thought strategically about this issue in order to establish a
clear political line, define each actor's responsibilities, and
name a national coordinator.
While it is true that the Ministry of Ecology (via the
Pollution and Risk Prevention Department, or "Pollution and Risk
Prevention Department") and the Ministry of the Interior (via
the DDSC or "Defense and Civil Protection Department") set up in
the spring of 2006 a national technical coordination group, its
effectiveness is limited insofar as it depends on the good will
of its members, due to a lack of any specific political
directives.
This lack of
coordination can engender absurdities. For example, the initial
French project in the Indian Ocean called for setting up a
national tsunami warning centre in La Réunion with its own
expert-assessment capacities, without having first considered
the needs of the other basins or the assessment means that
already existed. However, this project was never carried out due
to a lack of funding, but also because it turned out that
Météo France was not best suited to carrying out this
mission.
Similarly, the
purchase of new tide gauges and the updating of
already-installed devices in the four basins was the subject of
neither a global development plan, nor a prior analysis to
determine the most advantageous solution with regard to
installation speed and maintenance costs. Although SHOM was
unofficially put in charge of this task, this mission was never
the subject of any specific directive issued by its board of
directors, thereby engendering the observed delays.
b) The absence of funding
The French contribution to the tsunami warning systems also
runs up against a lack of available funding for the
necessary actions. Indeed, up until now, only the project for
setting up a national warning centre in the Indian Ocean
benefited from a suitable budget meant to cover all project
costs - even if your rapporteur believes that the funding made
available at the time was not necessarily spent on the most
important measures.
What's
more, this budget only provided for equipment financing.
However, numerous actions also necessitate operational funding.
For example, the rapid installation of new measuring devices
(seismic stations and tide gauges) and updating the already
existing devices require the services of one or more dedicated
engineers over a period of several months. Once the equipment
has been installed, the question then arises as to transmission
costs. For instance, the seismic data must be transmitted by
VSAT satellite, which proves quite costly. However, not only
must the bodies meant to carry out these tasks often pay
for these projects out of their own pockets, but also no
agreement has been signed between these same bodies and their
regulators specifically laying out their new tsunami-monitoring
missions. Therefore, their budgets make no provision for any
"tsunami projects", as such. As a result, it is very difficult
for them to devote money and personnel to missions that they are
not officially responsible for carrying out and for which they
receive no funding.
A few measures have been financed by several ministries. For
example, as has already been mentioned, the Ministry of Ecology
assigned BRGM with carrying out a study on the tsunami
vulnerability of the French coasts in the Mediterranean and West
Indies, as well as designing a database summarizing all
tsunamis to have struck metropolitan France and the West Indies.
Likewise, the Junior
Minister's Office for the Overseas Territories has financed
several pieces of equipment in the overseas territories,
including 4 tide gauges in Guadeloupe, sirens in Wallis and
Futuna and in New Caledonia, and a system of dissemination of
tsunami alerts.
Nevertheless, due to the lack of a global strategic vision and
an action plan put together by all the partners involved in
setting up a tsunami warning system, the sums invested remain
limited and there is a substantial risk of witnessing a
multiplication of small, unrelated projects whose continuity is
not guaranteed.
3. A change in French policy?
The Lisbon meeting of the ICG/NEAMTWS was marked by a
positive change in French policy, with France officially
announcing its interest to host a regional warning centre.
In addition, according to the information obtained by your
rapporteur, the French Prime Minister has agreed in
principle to the setting up of a national monitoring and warning
centre for coastal floodings of marine origin69(*),
which would also be used for tsunami-risk management. The
Department of the Sea, an institution under the direct authority
of the Prime Minister, would be put in charge of defining and
setting up this centre.
Your rapporteur fully supports this change in policy, even
if it is still too early to judge the concrete measures to be
taken by the French government. Indeed, the wait-and-see policy
that France has pursued up until now testifies to its profound
misunderstanding of the real stakes behind the setting up of a
tsunami warning system.
IV. RECOMMENDATIONS: FOR A STRATEGIC VISION OF TSUNAMI-RISK MANAGEMENT
A. SIGNIFICANT STAKES
While the main objective of setting up a tsunami warning
system is to protect the coastal populations, France's
participation is also to be explained by the existence of other
important economic, geostrategic and scientific stakes.
1. The security stakes
These stakes have already been discussed above; therefore,
your rapporteur would here simply like to point out that
while France takes great pride in its 10-million-km² exclusive
economic zone, divided between all of the world's oceans, this
territorial scattering also underlines its vulnerability to
tsunamis. Therefore, at the international level, the setting up
of tsunami warning systems constitutes a fortuitous opportunity
for France, because it allows it to ensure the effectiveness of
the system by multiplying the amount of seismic and sea-level
data available to the concerned countries and to mutualize the
investments in measuring devices.
However, considering the national security stakes at hand,
it is in France's best interest to play a central role
within the intergovernmental coordination groups, so that the
warning systems are quickly made operational and adapted to its
security needs.
What's
more, France has no choice but to define at the national level
the most adequate warning-system structure for the effective,
affordable protection of its entire coastline. If, as your
rapporteur hopes, France were to create a tsunami warning centre
for the Mediterranean, this centre would also have to be put in
charge of monitoring France's coasts in the Indian Ocean and
the Caribbean.
2. The economic stakes
The economic stakes must not be underestimated, either:
tourism constitutes an essential resource for our country. If
it were later to be revealed that the effects of a devastating
tsunami could have been limited by the existence of an
operational warning system, this would have a catastrophic
impact on our coasts' reputation.
In this regard, your rapporteur is convinced that risk
aversion in the developed countries will only increase - in
particular, due to their trust in science to protect them from
natural disasters. Therefore, we must stop believing that by
raising public awareness of natural risks, we thereby hinder
economic development; we should instead steer the discussion
towards a more general and positive context of natural
hazard-prevention policies.
Under the influence of the media, ever avid for powerful images
and prompt to point fingers, public authorities will come under
increasing social pressure to develop an effective
risk-prevention policy.
3. The geostrategic stakes
International coordination is essential for the successful
establishment of a tsunami warning system. Indeed, quickly
and reliably locating and assessing an earthquake and verifying
the generation of a tsunami necessitate both 1) the installation
of a large number of measuring devices, not only on French
territory, but also in the neighbouring countries and
earthquake-prone zones and 2) the availability and sharing of
seismic and sea-level data.
Therefore, France's more or less marked involvement in setting
up an operational warning system necessarily affects its
international influence and relations with the other countries.
During your rapporteur's
visits to the West Indies and French Polynesia, he became aware
of the strategic (yet largely unknown in metropolitan France)
role played by France's overseas territories and départements in the country's relations with the other countries present in these zones.
For example, the ICG/Caribbean-TWS brings together not only
the United States (concerned by the tsunami risk in
Florida) and the Caribbean countries, but also those countries
of South and Central America touching the Atlantic Ocean or the
Caribbean Sea.
Likewise,
via the ICG/Pacific, France is in permanent contact with Japan,
the United States, Australia and those South and Central
American countries with a Pacific shoreline.
However, numerous countries would like to cooperate more closely with France.
In the Pacific, France (essentially through LDG/Pamatai and
its civil-protection services) works in close collaboration
with Australia to develop a tsunami warning system in the
southwest Pacific. It has also established excellent ties with
Chile, which was the first country to equip its warning centre
with a TREMORS system. Because it was able to set up an
effective tsunami warning system in French Polynesia, the
neighbouring islands, as well as the International Tsunami
Information Centre in Hawaii often ask France for help in
setting up similar systems and to participate in international
conferences.
However, due to a lack of sufficient funding, French cooperation remains limited and sporadic.
In the Caribbean zone, France could make use of the
tensions that exist between the United States and Venezuela to
strengthen its influence in the region by playing the role of
mediator and acting as a counterweight to the United States.
Indeed, with the exception of the US, most member states of the
ICG/Caribbean-TWS do not have the funds necessary to effectively
contribute to the setting up of a warning system. If France
were to commit to becoming a regional warning centre alongside
that of Puerto Rico, it would considerably strengthen its
influence in this zone.
Furthermore, the setting up of a warning system in the
Mediterranean necessitates close cooperation between not only
the European Union countries, but also the countries of the
Mediterranean basin. The French presidency of the European Union
starting in July 2008, as well as France's special ties with
the North African countries should push our country to play a
major role.
Your rapporteur
insists on emphasizing the fact that up until now, France has
based its position on an erroneous calculation: namely, that by
not becoming involved in setting up the warning systems, it
would avoid having to help finance them. In reality, France will
nevertheless be forced to contribute to funding these systems,
without being able to take advantage of them. However, the above
examples demonstrate the extent to which France's active
participation could constitute an important diplomatic tool.
4. The scientific stakes
In developing a tsunami warning system, France can rely on
effective bodies that serve as models in their respective
fields. Nevertheless, scientific bodies are also concerned by
international competition and must constantly justify how they
make use of the funding they receive. It is clear that if France
were to play a driving role in the building of a warning system
in the Mediterranean, its scientific bodies and related
national institutions (CEA, IFREMER, SHOM, BRGM, Météo France,
etc.) would be closed involved in this project, thereby
strengthening their international credibility.
The role of the European-Mediterranean Seismological Centre
(which is hosted by CEA) could also be considerably
strengthened, if it were to house the regional warning centre
(under the management of CEA).
B. THE RECOMMENDATIONS
Taking into account what has already been said, your
rapporteur would like to make two types of recommendation:
structural recommendations that apply to all of the basins and
which together constitute as many prerequisites to an effective
French contribution to the setting up of a tsunami warning
system, and basin-specific recommendations, which take into
account the particularities of each sea or ocean and of the
varying tsunami-vulnerability of the French coasts.
1. Two introductory remarks
Your rapporteur would first like to make two remarks, that
the government should not only keep in mind while it
considers the preferable structure for a tsunami warning system,
but also communicate and comment upon.
The first remark concerns the particularities of the
tsunami hazard and their consequences for risk management.
Tsunamis are rare phenomena which require the use of
sophisticated detection devices and extremely reactive warning
systems, considering the brevity of the reaction times and the
risk of issuing false warnings. The choices made regarding the
warning system's final structure will depend on weighing the
system's costs against the frequency of the hazard. This
arbitration must be finalized in a transparent manner and
included in all of the early emergency-assistance plans.
The second remark underlines the limits of a warning system.
Contrary to popular opinion in France, there is no such
thing as "zero risk". Even if an effective tsunami warning
system is eventually set up, it will not be able to prevent the
loss of human life under any and all circumstances. Indeed,
while the impact of regional and tele-tsunamis can be greatly
mitigated, the means available to protect against local tsunamis
- which strike the coast only a few minutes after being
generated - are more limited. The only effective course to take
to protect against local tsunamis is to teach the concerned
populations the correct reflexes. It is essential, therefore,
that this message be communicated, in order to avoid any
misunderstanding between the civil-protection authorities and
the population.
2. The structural recommendations
The structural recommendations can be divided into four
main lines: defining a coherent warning system; establishing a
long-term, perennial budget; integrating the tsunami risk into a
multi-risk approach for the acquisition of sea-level measuring
devices; and experimenting (on a voluntary basis) with the
management of local-tsunami warnings.
a) Defining a coherent warning system
There are five preconditions to setting up a coherent
warning system: naming a general coordinator; using appropriate
measuring devices; relying on a thorough understanding of the
hazard; responding appropriately to the hazard; and raising
public awareness.
(1) Naming a general coordinator
Designing a tsunami warning system necessitates a great
many partners, with varied and sometimes contradictory
operating structures, interests and concepts of the final
tsunami warning system. A general coordinator is therefore
doubly necessary.
The
general coordinator would be responsible, firstly, for defining,
along with the various bodies associated with the project, the
project's main lines, in order to ensure its internal coherency.
He/she would therefore have to finalize the content of and
coordinate France's contributions in the four basins. He/she
would also ensure, in collaboration with the National Committee
of the Intergovernmental Oceanographic Commission, that France
participates at the meetings of the 4 intergovernmental
coordination groups and that it is represented in each working
group. The National Committee must therefore enjoy sufficient
funding to finance the participation of the French delegates at
these meetings and assume the role of the secretariat.
Secondly, the general coordinator would be responsible for
determining everyone's responsibilities and missions and
establishing a project calendar.
There are two conceivable avenues of reflection:
- The creation of an interministerial delegation modeled
after the Post-Tsunami Interministerial Delegation: this
structure has proved effective in carrying out a concrete
project involving a great many partners over a set period of
time.
- The assignment of
this managerial role to the Department of the Sea: several
arguments could be made in favour of this solution. Firstly,
this department is under the direct authority of the Prime
Minister. This privileged position provides it with an
indisputable authority over its partners and allows it to speed
up arbitration in the event of a disagreement. Secondly, this
department is used to working with several other bodies
concerned with setting up a warning system (SHOM, IFREMER) and
is therefore well familiar with how they operate. Finally, the
success of Extraplac70(*)
(coordinated by the Department of the Sea) testifies to its
ability to manage a similar project. It appears likely that the
government will choose this solution.
While it is not the role of your rapporteur to finalize all
of the details of the final structure of France's future
tsunami warning system, he nevertheless believes that it should
include the creation of a national warning centre managed by
CEA, whose short-term field of operations would cover warnings
in the Mediterranean/northeast Atlantic, the Caribbean and the
Indian Ocean in the event of a tsunami estimated to arrive 15
minutes or more after the detection of the tsunami-generating
event. Once this system is up and smoothly running, a second
stage could extend the mission of the national warning centre to
cover local tsunamis in predefined zones equipped with the
necessary measuring and warning devices.
Furthermore, this national warning centre will also have to
act as a regional warning centre in the western
Mediterranean, the Caribbean and the western Indian Ocean zone,
in collaboration with the other regional centres.
(2) Using appropriate measuring devices
Every effective warning system relies on seismic stations,
tide gauges and tsunamimeters that transmit their data in
real-time. In addition, taking into consideration the
tsunami-risk linked to landslides necessitates the installation
of such specialized sensors as hydrophones.
With regard to tide gauges, there exist several networks. Via the RONIM71(*)
network, SHOM manages 30 tide gauges scattered about
metropolitan France, the West Indies, the Indian Ocean and the
Pacific. LEGOS72(*) is responsible for the ROSAME73(*)
network, which includes 4 tide gauges installed off of
D'Urville and Amsterdam Islands and in the Crozet and Kerguelen
Islands. Furthermore, the departmental bodies responsible for
public works, the harbour authorities and certain local
governments also manage tide gauges. Finally, within the context
of tsunami warnings, the OVSG ("Vulcanologic and Seismologic
Observatory of Guadeloupe") is creating its own network in
Guadeloupe and CEA proposes that tide gauges must be installed
in the Pacific in order to set up a tsunami warning system to
protect New Caledonia and Wallis and Futuna.
Many of the Overseas Territories' tide gauges are - or will
soon be - capable of transmitting their data in real-time.
On the other hand, among those tide gauges managed by SHOM in
metropolitan France, only Le Conquet device meets this
criterion. However, according to the information gathered by
your rapporteur, 13 tide gauges belonging to SHOM (including 11
in metropolitan France) could be rapidly updated to transmit
their data in real-time, because they already have the necessary
outlets. The estimated cost is €2,500 in equipment and one work
day per tide gauge. It is therefore urgent that SHOM's
governing body provide it with the necessary means to rapidly
adapt the tide gauges in question.
In the Mediterranean, only 2 tide gauges could rapidly
transmit their data in real-time: that of Port-Vendres and that
of Sète. It is therefore essential to accelerate SHOM's planned
replacement in the medium term of the sea-level measuring
devices off Ajaccio, Toulon, Marseille and Nice, so that they
may be integrated into the warning system before the end of
2008.
Furthermore, your
rapporteur insists on the fact that data transmission can be
free, if the tide gauges allows for the direct sending of data
via the Global Telecommunication System. Therefore, all that
needs to be done is to acquire a receiving system to receive the
data from all of the tide gauges using GTS. This system, whose
energy source and transmissions are autonomous, is particularly
recommended for the more isolated islands and coastlines, which
is the case with many sites in the Overseas Territories and in
foreign countries.
Given the multitude of sea-level networks, it is particularly
important to create a "one-stop" set up, by designating a single
body in charge of centralizing and archiving the data, as well
as making it available to all interested users. In addition,
this body could advise all those organizations interested in
installing sea-level measuring devices in order to ensure that
the planned devices meet the criteria defined by the Global
Sea-Level Observing System (GLOSS), and thereby serve as many
applications as possible.
Your rapporteur would like to point out that SHOM is
responsible for navigational security in the French zones via
the establishment of nautical charts and tide tables. Therefore,
all bathymetric and tidal information is supposed to be
transmitted to SHOM - though, in reality, this is not done by
the various organizations on a systematic basis. Indeed, SHOM
only learned of the existence of the network managed by the OVSG
after these tide gauges were damaged by Hurricane Dean.
To get round this difficulty, the GLOSS national representative74(*)
has taken charge of this mission. However, this solution is not
ideal, because it relies on the good will of a single
individual, which renders the initiative very vulnerable over
time.
Therefore, SHOM
should be officially commissioned to coordinate the sea-level
measurement activities in France by its board of governors and
it should be provided with all the financial and human-resource
means necessary for it to carry out this task.
In this regard, your rapporteur would like to point out
that the board of governors is currently negotiating SHOM's
"objective-means agreement" for the next five years. It would
therefore be appropriate to take into account during this
process France's needs with regard to the national coordination
of its sea-level measuring activities and the network's rapid
updating to real-time. The presence of a representative of the
Ministry of Ecology and Sustainable Development and a
representative of the Ministry of the Interior and of the
Overseas Territories on the governing board of SHOM should raise
this board's awareness of the fundamental role that SHOM is
brought to play in rendering the tsunami warning system
effective.
With regard to
the seismic stations, France's broadband network should be
installed within a few years in metropolitan France. It should
correctly cover our territory, while the network's
communications are switched over to satellite. Nevertheless, the
data-transmission costs are great and should be included in the
operating costs of the various organizations responsible for
managing the seismic stations.
Finally, the French Mediterranean coastline will only be
well protected if at least two tsunamimeters are installed off
the coast of Algeria. Other tsunamimeters will be necessary in
the Mediterranean basin, including one between Corsica and the
mainland and another in the northeast Atlantic. The significant
costs engendered by these measuring devices in terms of
equipment, installation and maintenance should be shared out at
least partially at the European level.
(3) Relying on a thorough understanding of the hazard
In order to be effective, a tsunami warning system must
rely on a thorough understanding of the hazard. While several
studies have already been carried out and numerous simulations
have been developed, this work has been entrusted to numerous
research institutes without any overall coordination. Therefore,
it would be advisable to make an inventory of the past and
present research and to finalize a guiding line concerning the
existing needs.
Several avenues should be given priority:
Firstly, a deeper understanding of the sources is
necessary. The study carried out by BRGM on the vulnerability of
the French coasts in the Mediterranean and the West Indies
represents a first step in this direction. However, according to
the information obtained by your rapporteur, the zones chosen
and the associated earthquakes are a subject of contention in
the scientific community. Therefore, the studies seeking to
specifically identify the tsunami-vulnerable zones must be
continued.
With regard to
landslides, the research is less complete, even if remarkable
studies have been carried out, such as those by the GIS/CURARE
in the Marcel Cirque. Therefore, this long-term work must also
be continued.
The creation
of a tsunami database, begun by BRGM, must also be brought to
completion. Nevertheless, its current specifications should be
modified. Up until now, BRGM has only used written documents
which mention an event whose characteristics resemble those of a
tsunami. However, this approach is too limited in scope to
include very old tsunamis or those to have struck more isolated
areas. The Solomon Islands tsunami of April 2007 is a case in
point: to judge by the local press, this tsunami had hardly any
effect on New Caledonia. However, a mission meant to gather
eyewitness accounts of this event revealed several phenomena
characteristic of a tsunami (a retreating sea, tidal bores,
eddies in the harbours) that no one had thought to report since
they had caused no material damage or loss of life. On-site and
post-tsunami studies are therefore essential for a better
understanding of this phenomenon.
With the prospect of setting up a warning system, modelling
is also essential to understanding a tsunami's impact on a
given coast. However, it is only effective if the bathymetry
near the coast is sufficiently precise to take into account site
effects. But, the sea charts near the coasts are incomplete. In
1998, a marine campaign carried out by IPGP on an IFREMER ship
was meant to chart the underwater relief around Martinique and
Guadeloupe. Unfortunately, due to a dockers' strike, the
multi-beam echo sounder was not delivered in time and the team
was unable to chart the zone between 0 and -200 m. A
24-nautical-day mission would be necessary to complete the
current bathymetry of this area, with each day at sea costing
anywhere between €10,000 and €20,000.
There currently exist several national programmes, for the
most dedicated to territorial waters (12 nautical miles):
- The Litto 3 D project launched conjointly by SHOM and the
IGN ("National Geographic Institute") for that section
between -10 and +10 m around the coastline.
- IFREMER's REBENT project, for pilot zones in the band located between sea level and -20 m.
- One-off projects, via scientific programmes or programmes
carried out with the support of the regional councils, to
map shallow formations.
The
Litto 3 D programme seeks to precisely map the coastal band
between +10 m for the terrestrial section and 6 nautical miles
for the marine section. The surveying is carried out via an
airborne system (bathymetric LIDAR) and a hydrographic launch
equipped with a multi-beam echo sounder, allowing it to achieve
an up-until-now unequalled precision that is essential for
effective modeling.
The
bathymetric and altimetric data collected by the two institutes
has been compiled, adapted to be presented in a "seamless"
manner75(*),
and made available via the Géoportail server. In addition,
two bathymetric-survey programmes have been carried out in
the Gulf of Morbihan and off of Toulon, in order to demonstrate
the quality of the charts obtained via these modern measuring
devices.
Your rapporteur
supports this project, which has the double advantage of 1)
having made an inventory of what already exists, in order to
avoid any redundancies, and 2) providing precise surveys, which
are indispensable to expertly manage and prevent
coastal-submersion risks of marine origin. In the medium term,
the bathymetric surveys must be completed to cover the zone
between 0 and -200 m.
In
addition, considering the ever greater role played by the local
governments in the collection of bathymetric data, we should
avoid their financing the acquisition of data that risks not
meeting the standards established by SHOM and the IGN.
(4) Responding appropriately to the hazard
The setting up of a warning centre capable of issuing a
message 24 hours a day, 7 days a week indicating the occurrence
of an earthquake liable to have generated a tsunami constitutes
but the first step in building an effective warning system. The
said message must also reach the competent authorities in
charge of organizing emergency assistance and these same
authorities must know exactly what needs to be done at every
level, as is the case for the ORSEC plans. Considering the very
short reaction times and the many organizations involved76(*), there can be no place for improvisation.
The creation of inundation and evacuation maps must be
encouraged, because they allow, in particular, for a prior
evaluation of the extent of damages and an identification of the
routes that can be used for emergency assistance efforts. The
principal harbours and densely-inhabited coastal areas must be
the first zones covered.
Furthermore, training exercises are indispensable to identify
any problems/malfunctions and improve the system's
effectiveness.
The question
of installing sirens to warn the population must also be
raised. Your rapporteur is well aware that this is a very
sensitive issue for the local elected representatives.
Nevertheless, the sirens' effectiveness should be underlined.
Indeed, when the population is scattered about the territory, it
is impossible for the civil-protection services to warn
everyone threatened in time. In this case, sirens become
indispensable. In addition, one must remember that the
traditional communications network is often rendered useless,
either because the tsunami-generating earthquake is near enough
to affect the telephone and/or electricity network, or because
it is saturated as soon as the first warning messages are
issued. Therefore, the option of installing sirens must be
studied during the definition of the future national warning
system by the steering committee coordinated by the Department
of the Sea.
Finally, the
specialized emergency-assistance plans must be defined in the
French West Indies, the Mediterranean/northeast Atlantic, New
Caledonia and Wallis and Futuna.
(5) Raising public awareness
This question has already been raised; however, it remains
crucial, insofar as it clearly represents the weak link in
the warning chain.
Your
rapporteur has already discussed the public-awareness policies
carried out at the national level (essentially meant to raise
awareness of the tsunami risk among young people), but also at
the local level. He draws from these experiences the following
conclusion: if it is necessary to improve the public awareness
campaign at the national level, targeting the entire French
population, then it is essential to also carry out an
information campaign specifically targeting the most at-risk
populations: namely, the coastal populations, both permanent
residents and tourists.
It is not up to your rapporteur to define the contents of
the public-awareness campaigns. However, he believes that in
order for them to be effective, they must be repeated and use
several communication vehicles in order to touch a diverse
public (exhibitions, news reports, scientific television/radio
programmes, conferences).
At the local level, the effectiveness of the public-awareness
campaigns will depend strongly on the involvement of the local
stakeholders (local governments, chambers of commerce and
industry, tourist offices, hotels, harbour authorities,
lifeguards, etc.). Your rapporteur is aware of the reticence of
the local elected officials and the tourist professionals to
communicate on the tsunami risk, on the pretext that the subject
scares away tourists.
Your
rapporteur disagrees with this argument. Indeed, every hotel
displays an emergency evacuation map in the event of a fire, yet
no one has observed that this discourages tourists from staying
at hotels - even though, as in the case of a tsunami, a fire is
a relatively low-risk event that could have dire consequences.
In reality, a well-thought-out communication campaign - one which describes the hazard77(*),
soberly explains its mechanisms, and indicates the simple
measures to take to protect against it - can only have a
positive effect on the community broadcasting the information,
because it testifies to the local government's concern for
the safety of the area's inhabitants. This information can be
provided in the form of brochures and posters, in both French
and English; it can also be included in magazines presenting the
activities of the local government. In addition, a partnership
with the press must be developed, so that any measures taken by
the local government to protect the population from tsunamis
receive media coverage.
Finally, raising awareness of the tsunami risk among
children and teenagers should be a priority. In coastal zones
particularly vulnerable to tsunamis, the teaching materials used
must refer to real, historical phenomena and teach the right
reflexes in a fun manner.
For schools located in inundation-prone areas, evacuation
exercises represent the best means of educating the children.
b) Establishing a long-term, perennial budget
A tsunami warning system cannot be set up and function
properly in the long-term if it does not benefit from a
perennial budget that takes into account not only the initial
equipment costs, but also the operating costs (salaries,
missions, equipment maintenance, telecommunications, updating of
software, etc.).
This
funding must be clearly defined, in agreement with the various
bodies involved in setting up the system and which must also be
officially commissioned to carry out their new missions linked
to tsunami monitoring and the issuance of warnings.
In addition, the government must clearly commit itself to
the sums it is willing to spend in the long-term to maintain a
tsunami warning system, in order to avoid this system being
questioned a few years after its creation.
c) Integration of the tsunami risk into a multi-risk approach?
As the head of CEA/DASE pointed out, the future national
tsunami warning centre will be confronted with the same
constraints as the national centre for the monitoring of nuclear
explosions: although the surveilled event occurs only rarely,
when it does, the information on it must be gathered quickly and
reliably; this requires high-performance equipment that is also
sometimes redundant (for greater security).
Therefore, the idea behind extending the mission of the
tsunami warning system to include the monitoring and prevention
of other coastal-submersion risks of marine origin is to make
the best use of the significant investments required to set up a
tsunami warning system and to ensure the longevity of the
government's financial commitment by strengthening the
legitimacy of the warning centre through a multiplication of its
missions.
This idea is
also based on the observation that tide gauges are used to
verify and quantify all coastal-inundation risks. Communicating
on the multiple applications of the sea-level measuring devices
should therefore contribute to justifying their acquisition and
updating. Similarly, a precise cartography (both bathymetric and
altimetric) of the coastal zones can be used to both forecast
and manage all coastal-inundationing risks of marine origin.
While your rapporteur
recognizes the pertinence of these arguments, he nevertheless
remains convinced that the modalities of integrating a tsunami
warning system into a multi-risk warning system are much more
difficult than the supporters of this approach believe, insofar
as the "competent" body for analyzing the hazard and issuing the
warning to the concerned civil-protection services differs
according to the nature of the risk.
Most tsunamis for which an effective warning is conceivable
are generated by an earthquake. The warning system must
therefore be able to be set off by a body specialized in the
monitoring and evaluation of earthquakes, such as CEA in France
or INGV in Italy.
The other
coastal-inundationing risks of marine origin (storm surges,
cyclonal swells, rising sea level) are all of meteorological
origin and must therefore be managed by such weather services as
Météo France.
How would
these different areas of competence be divided up within the
framework of a multi-risk system here in France? Would one
organism be called upon to absorb another?
Your rapporteur would like to point out that in Japan, the
weather services are responsible for managing all natural
hazards and, as a result, include a seismological department.
Nevertheless, this structure has not been adopted in France and
the obstacles with which such a reform would be confronted must
be weighed against the gains that could be made. In this regard,
your rapporteur would like to point out the failure to set up a
national multi-risk warning centre in La Réunion, which was
meant to rely on Météo France. While it is true that Météo
France issues tsunami as well as cyclone warnings, in reality,
it is a Focal Point that is content with retransmitting the
bulletins issued by PTWC and JMA, due to a lack of seismological
expertise.
Therefore, your
rapporteur believes that, in the short term, the multi-risk
approach must primarily seek 1) the acquisition of a network of
"multi-use" measuring devices whose data must be made available
to all risk-management bodies and 2) the mutualization of the
data-transmission means.
d) Voluntary experiments with the management of local-tsunami warnings
Throughout this study, your rapporteur has insisted on the
fact that it is particularly difficult to predict the impact
of local tsunamis: considering the short reaction times, the
warning centres hesitate to assume this responsibility, insofar
as they run the risk of seeing their messages arrive after the
wave has already struck the coast.
During the last session of the ICG/NEAMTWS in Lisbon, the
member states agreed that the regional warning centres would
only deal with those tsunamis with a reaction time of over 15
minutes. For tsunamis with shorter reaction times, the
responsibility for issuing the warning falls to the national
centres. Indeed, issuing an effective warning when the reaction
time does not exceed 15 minutes requires a much denser network
of sensors than that necessary to monitor regional tsunamis, as
well as an automated warning system using sirens. This therefore
entails a significant investment, which must be related to the
frequency of the expected hazard. In addition, the warning's
success is not guaranteed and depends more than ever on the
correct reaction of the population and therefore on raising the
public's awareness of the tsunami risk.
Therefore, it would be unrealistic to want to generalize a
local-tsunami warning system to all of France's coasts.
However, your rapporteur believes that in certain zones that are
exposed to a high local-tsunami risk, and whose local elected
officials are well aware of the risk, a warning system suited to
local tsunamis could be experimented with.
In metropolitan France, the greater Nice area could be
interested in this trial: in this area, the local tsunami hazard
represents a real risk, as was demonstrated on 16 April 1979;
this zone is particularly vulnerable, considering its dense
coastal population all year long, with peaks in the summer; our
understanding of the hazard in this zone is good, thanks to the
many geophysical studies that have already been carried out on
gravitational instabilities in the Marcel Cirque; finally, this
region can be considered a model in terms of raising the local
government's awareness of the tsunami risk.
Therefore, an experiment could be developed, that brings
together in close collaboration various government services
(in particular, the civil-protection services), the key
scientific bodies studying tsunamis, local governments and
harbour authorities, as well as manufacturers to design an
effective data-transmission system. If the trial proves
successful, the system could be extended to other coastal
regions, both in metropolitan France and overseas.
In this regard, your rapporteur would like to point to the
project elaborated by the "marine" and "territorial risk and
vulnerabilities" competitiveness clusters of the
Provence-Alpes-Côte d'Azur region, which seeks to set up a
RATCOM ("Tsunami Warning System for the Mediterranean Coasts").
This project's objective is to establish an automated warning
system for local tsunamis.
The proposed system is designed around two main functional components:
- A "descending component", which seeks to offer effective
and reliable communication means allowing for the
transmission of warnings via first a local network, then a mass
broadcast.
- A "rising
component", which is meant to deliver - based on automatically
processed measurements gathered both at sea and on land - a
qualified, coordinated tsunami warning bulletin, meant to
minimize, in particular, the chance of issuing a false warning.
In addition to the processing of this data in real-time,
decision-making tools based on prior modelling will have to be
created and made available to those bodies responsible for
crisis management and intervention.
3. Basin-specific proposals
a) In the Mediterranean/northeast Atlantic
CEA must be commissioned to act as the national
representative of the ICG/NEAMTWS, as well as the national and
regional tsunami warning centre. Currently, no fewer than 7
Mediterranean countries78(*)
have officially expressed their interest in becoming a regional
warning centre (without necessarily having the financial and
human-resource means), while 2 to 3 regional centres would
seem to be sufficient. Therefore, France should perhaps propose
a solution that is sensitive to the national interests of the
other interested countries. This would amount to using a
European-based structure, such as the European-Mediterranean
Seismological Centre located at CEA's Bruyères-le-Châtel site,
to house the regional warning centre that France would create,
which would nevertheless be managed by CEA/DASE.
Furthermore, it is urgent to transmit in real-time the data
gathered by the 11 metropolitan tide gauges that already
have the appropriate outlet and to finish modernizing the
remaining tide gauges managed by SHOM before the next meeting of
the ICG/NEAMTWS in October 2008. This network should be
complemented by two stations in Corsica (Bonifacio and Porto
Vecchio). It should be pointed out that, in order to protect
France's costs, the national warning centre will have to receive
real-time data from some twenty tide gauges spread out between
Spain, Portugal, Sardinia, Morocco, Tunisia and Algeria.
Therefore, France should verify that the already-existing
stations are updated or, if necessary, propose the installation
of new stations.
In
the short term, France will have to ensure the installation of
two tsunamimeters north of Algeria in order to effectively
protect France's coasts. For this to be done quickly, France
will have to declare itself willing to finance the station's
equipment and installation and negotiate with the other member
states of the ICG/NEAMTWS a mutualization of the maintenance
costs.
In the medium term,
we should come to a decision regarding the opportunity of
setting up a warning system for local tsunamis in well-defined
zones and, if need be, carry out a feasibility study on the
automated management of this type of warning.
In addition, the setting up of a tsunami warning system
must represent a priority of the French presidency of the
European Union starting in July 2008 and mobilize all the member
states and concerned directorate generals of the European
Commission, in order to define and finance a plan for the
modernization of the national tide gauges and the installation
of tsunamimeters.
In order
to overcome the difficulties encountered with regard to the
North African countries' reticence to share their seismic data,
it seems essential to launch a diplomatic mission involving both
the Ministry of Foreign Affairs and the French presidency. On
this occasion, a bilateral or European partnership could be
proposed, so as to speed up the installation of tide gauges and
tsunamimeters off the North African coast.
Finally, the specialized emergency plan for tsunamis must
be finalized for the metropolitan coast by the civil
protection authorities, in collaboration with CEA for its
scientific expertise.
b) In the Caribbean
Your rapporteur believes that France must become more
involved in the work being carried out by the ICG/Caribbean-TWS.
It must therefore attend each session and be represented in
each working group.
Your
rapporteur also supports the initiative launched by the French
delegation during the Venezuelan session to host the
ICG/Caribbean-TWS session in 2009. This date could serve as a
deadline for defining the French strategy with regard to
regional tsunami warnings in the West Indies, as well as the
installation and updating of the seismic stations and tide
gauges required for the protection of the French West Indies.
Your rapporteur would like to once again point out that the 3
tide gauges managed by SHOM have to be rapidly brought up to
date to transmit their data in real-time79(*)
and that 3 supplementary tide gauges have to be installed east
of La Désirade, south of Martinique and north of
Guadeloupe.
Furthermore, we
must ensure that the sea-level network that is currently being
installed by the OVSG could serve other applications and,
consequently, meet the criteria set by GLOSS in its sea-level
measuring devices manual. The data gathered by these tide gauges
should also be transmitted to SHOM for archiving.
Furthermore, we must make sure that the planned national
tsunami warning centre manages the tsunami warnings in the
Caribbean, for those tsunamis with a reaction time of greater
than 15 minutes (from the time of their generation to their
arrival on the coast). On this occasion, it will certainly be
necessary to clarify the respective tasks of IPGP (responsible
for seismic monitoring in the West Indies) and CEA (responsible
for issuing the tsunami warnings).
Once the system is up and running, CEA should be
commissioned to carry out a feasibility study on extending its
mission, for it to become the regional tsunami-warning centre
for the Caribbean zone, in cooperation with Puerto Rico, PTWC
and the ATWC.
In the medium
term, we must study the possibility of setting up an automated
warning system for local tsunamis in certain coastal zones which
remain to be determined and, if need be, carry out an
experimentation in partnership with the interested local
governments.
Finally,
during the last session of the ICG/Caribbean-TWS, it was
observed that France has up until now focused its attention on
Martinique and Guadeloupe, effectively ignoring French Guiana
and Saint Martin. This situation should therefore be clarified
by launching a study on these zone's tsunami vulnerability and,
if need be, integrating them into the national tsunami warning
strategy for the West Indies (installing sea-level measuring
devices and seismic stations, defining a specialized
emergency-assistance plan, raising public awareness, etc.).
c) In the Indian Ocean
Your rapporteur has already observed that €305,000
attributed to Météo France for the creation of a national
tsunami warning centre in the Indian Ocean remain to be spent,
due to the modification of the initial project. Therefore, this
money must be recovered and redirected to the budget dedicated
to setting up a coherent, perennial national warning system. A
portion of this sum could also be directed to the installation
of a tide gauge in Madagascar (initially planned but never
carried out) and a second station in La Réunion.
Your rapporteur regrets that France has effectively ceased
to participate in the ICG/IOTWS sessions and recommends that
it once again become involved in the work of the
ICG/Caribbean-TWS and the working groups that this body has
formed.
Furthermore, your
rapporteur would like to see the mission of the planned national
tsunami warning centre extended to cover the French territories
in the Indian Ocean.
In
addition, once the system is up and running, CEA should be
commissioned to carry out a feasibility study on extending its
mission, for it to become the "regional tsunami-watch provider"
for those countries of the western Indian Ocean, in cooperation
with other "regional tsunami-watch providers".
d) In the Pacific
In order to complete the warning system that already exists
and effectively protect New Caledonia and Wallis and
Futuna, your rapporteur supports setting up the warning system
for the southwest Pacific presented earlier, which requires the
installation of 15 tide gauges and 1 tsunamimeter, if
Australia's planned tsunamimeter proves worthless for the
protection of New Caledonia.
Your rapporteur would like to once again point out that the
number of necessary sirens must be decided upon and an
equipment-development plan for the islands finalized, in
collaboration with the High State Authority of New Caledonia,
the Overseas Ministry and the local elected officials of the
French territories in this zone.
In addition, the civil-protection authorities must finalize
the specialized emergency plan for New Caledonia and for
Wallis and Futuna.
The
system in French Polynesia must also be completed with the
installation of 3 tide gauges on the furthest boundaries of
Polynesia, transmitting their data in real-time.
Finally, your rapporteur believes that it is in France's
best interest to respond to the cooperation requests of the
Pacific-zone countries. He therefore proposes providing CEA with
an official mandate, so that LDG/Pamatai can take on a mission
of cooperation with regard to tsunami warnings and enjoy
sufficient funding for it to carry out several assessment and
training missions per year.
SUMMARY OF PROPOSALS
1. The proposals applying to all four basins:
- Commission CEA to act as the national tsunami warning
centre for the Mediterranean/northeast Atlantic, the West
Indies and the Indian Ocean and to develop a method for
forecasting regional and teletsunamis.
- Allow the future national warning centre to also act as a
regional warning centre in the western
Mediterranean/northeast Atlantic, the West Indies and the
western Indian Ocean, in collaboration with the other regional
warning centres present in each basin.
- Create a steering committee coordinated by the Department
of the Sea, responsible for setting up a national tsunami
warning system and made up of representatives of:
· those ministries concerned by tsunami-risk management (Ministry of the Environment and Sustainable Development; Ministry of the Interior and the Overseas Territories; Ministry of Foreign Affairs; Ministry of Higher Education and Research; Ministry of Education);
· those bodies competent in this domain (CEA, Météo France, SHOM, IFREMER, BRGM, CNRS, CETMEF80(*), IPGP, ANR, Conservatoire du Littoral, etc);
· the local governments of tsunami-vulnerable areas.
- Provide the Department of the Sea with a long-term budget
to finance the setting up of a tsunami warning system
(equipping the system with tide gauges, seismic stations and
tsunamimeters capable of transmitting their data in real-time;
funding those bathymetric-survey programmes judged
indispensable; setting up GPS geodesic networks to be able to
precisely record strong earthquakes).
- Strengthen the means available to the National Committee
of the Intergovernmental Oceanographic Commission, to allow
it to coordinate the French position during the sessions of the
four intergovernmental coordination groups for setting up a
tsunami warning system and ensure that France is represented in
each working group.
-
Complete the "objective agreements" of those bodies involved in
the tsunami warning system, so that this mission is made
officially known and is funded by a specific line of credit.
- Provide SHOM with a mandate
to coordinate the sea-level measurement activities in France and
adapt its network of tide gauges so that their data is
transmitted in real-time.
-
Complete the bathymetric surveys to cover the zone from 0 to
-200 m in both metropolitan France and overseas.
- Improve the satellite-based tsunami observation system by
systematically including a specialized tsunami-observation
mechanism in all low-orbit satellites scheduled for launch over
the coming years.
- Plan on
regularly updating the tsunami database entrusted to BRGM and
take into account any on-site studies carried out over time.
- Encourage the National
Research Agency to favour studies on geological and coastal
hazards - in particular, those concerned with the evaluation and
forecasting of tsunami-generating events (earthquakes,
underwater landslides, cliff collapses).
- Following each tsunami, finance post-tsunami, on-site
surveys in both metropolitan France and overseas.
- Carry out training exercises to test the effectiveness of
the warning system, taking into account the entire
decision-making chain, and identify any possible
problems/malfunctions.
-
Create inundation and evacuation maps for the main harbours and
densely-populated coastal areas, to serve as decision-making
tools for emergency-assistance management and urban development.
- Evaluate the need to install sirens to alert the population of each basin.
- Regularly raise public awareness concerning natural
hazards, via exhibitions, news reports, scientific
television/radio programmes, conferences, etc.
- Involve the local elected officials, harbour authorities
and tourist professionals in setting up public-awareness
campaigns for the harbours and coastal zones.
- Integrate natural-hazard education in the school programmes.
- Experiment with the management of certain local-tsunami
warning systems, in cooperation with the interested local
governments.
2. The basin-specific proposals
In the Mediterranean/northeast Atlantic zone
- Update to real-time the 11 tide gauges that already have
the appropriate outlet, finish updating the Toulon,
Marseille, Nice and Ajaccio tide gauges, and complete the system
by installing two new tide gauges in Corsica (Bonifacio and
Porto Vecchio) before the next session of the ICG/NEAMTWS in
2008.
- Install 2 tsunamimeters north of Algeria.
- Finalize the specialized tsunami emergency-assistance
plan for the metropolitan coast, by relying on the scientific
expertise of CEA.
- Make
the setting up of a tsunami warning system a priority of the
French presidency of the European Union starting in July 2008
and mobilize all the member states and concerned directorate
generals of the European Commission, in order to define and
finance a plan for the modernization of the national tide gauges
and the installation of tsunamimeters.
- Direct French diplomacy towards encouraging the North
African countries to share their seismic and sea-level data.
- Consider a bilateral or
European partnership to accelerate the equipping of the North
African coasts with tide gauges and tsunamimeters.
- Carry out a feasibility study on the automated management
of local-tsunami warnings in certain, particularly
vulnerable zones, in collaboration with the civil-protection
services, local governements, concerned harbour authorities and
associated manufacturers, and, if need be, carry out an
exercise.
In the Caribbean
- Update the 3 tide gauges managed by SHOM, integrate the
network of tide gauges currently managed by the OVSG and the
local governments into the warning system, and finance the
installation of 3 additional tide gauges east of La Désirade,
south of Martinique and north of Guadeloupe.
- Evaluate the need to install sirens to alert the population.
- Finalize the specialized tsunami emergency plan for the
West Indies, by relying on the scientific expertise of CEA.
- Clarify by agreement the respective tasks of IPGP
(responsible for seismic monitoring in the West Indies) and CEA
(responsible for issuing tsunami warnings).
- Carry out a feasibility study on the automated management
of local-tsunami warnings in certain, particularly
vulnerable zones, in collaboration with the civil-protection
services, local governments, concerned harbour authorities and
associated manufacturers, and, if need be, carry out an
experimentation.
- Clarify
the situation in French Guiana and Saint Martin by studying the
tsunami vulnerability of these zones and, if need be, integrate
them into the national tsunami warning strategy for the West
Indies (installing sea-level measuring devices and seismic
stations, defining a specialized emergency-assistance plan,
raising public awareness, etc.).
- At the international level, ensure that France is
represented in the working groups of the ICG/Caribbean-TWS
during each of its sessions, especially if France plans on
becoming a regional tsunami warning centre.
- Host the ICG/Caribbean-TWS meeting in 2009.
In the Indian Ocean
- Redirect the €305,000 attributed to Météo France for
the creation of a national warning centre in the Indian Ocean
(and which will not be spent, due to the modification of the
initial project) to the budget for setting up a coherent,
perennial national warning system.
- Ensure the installation by SHOM of a tide gauge in
Mayotte and Madagascar, as specified in the agreement signed
between the Ministry of Foreign Affairs and Météo France, and
complete the system by installing a second tide gauge in La
Réunion.
- At the
international level, ensure that France is represented in the
working groups of the ICG/IOTWS during each of its sessions,
especially if France plans on becoming a regional tsunami
warning centre.
In the Pacific
- Set up the previously presented warning system in the
southwest Pacific, which necessitates the installation of
15 tide gauges and 1 tsunamimeter.
- Determine the number of necessary sirens and finalize an
equipment-development plan for the islands, in collaboration
with the High State Authority of New Caledonia, the Overseas
Ministry and the local elected officials of the French
territories in this zone.
- Finalize the specialized tsunami emergency plan for New Caledonia and Wallis and Futuna.
- Install 3 tide gauges transmitting their data in
real-time on the borders of French Polynesia, in order to
complete this zone's warning system.
- Provide CEA with an official mandate, so that LDG/Pamatai
can take on a mission of cooperation with regard to tsunami
warnings for the Pacific region and provide it with sufficient
funding for it to carry out several assessment and training
missions per year.
CONCLUSION
Immediately following the Sumatra tsunami, France committed
itself to contributing to set up tsunami warning systems in
the Indian Ocean, the Mediterranean/northeast Atlantic zone and
the Caribbean.
Three years
later, things have not turned out nearly as well as initially
expected: insofar as La Réunion is principally threatened by
regional and tele-tsunamis, with relatively long reaction times,
the warning system set up is globally effective. Currently,
Météo France receives the messages issued by PTWC and JMA, which
it then transmits unaltered to the prefecture. However,
contrary to the stated objectives during the definition of the
Indian Ocean warning centre's mission in 2005, there is no
scientific body carrying out complementary evaluations. In
addition, the data transmitted by France to the international
warning centres is limited due to the delay in installing and
updating the tide gauges and seismic stations.
In the Mediterranean and the Caribbean, the situation is
worrying because France remains completely powerless in the
face of an eventual tsunami: France has no measuring devices for
the detection of tsunamis, no specialized emergency plan has
been finalized by the civil-protection services, and due to
insufficient public awareness it is more than likely that the
local populations would not know what to do in the event of a
tsunami.
However, France's coasts could be struck by a tsunami at any time.
Tsunamis certainly represent a rare phenomenon; for
example, a devastating tsunami is estimated to occur once every
century in the Mediterranean basin, the last dating back to 1908
in the Straight of Messina and claiming 35,000 victims.
Therefore, must we set up a tsunami warning system, given the
relatively low chance of such an event occurring?
Following the Sumatra tsunami, the response of the
international community, including France, was yes, we should.
Indeed, all countries agreed that they could not remain
inactive, when it is immediately possible to limit the dramatic
consequences of a tsunami on the coastal populations. Therefore,
we should respect the commitments we have made and set up the
tsunami warning systems planned for each basin.
France's widely scattered territories and the vulnerability
of each of its coasts in all four basins should lead it to
play a driving role in the elaboration of these warning systems.
Indeed, France must set up its own national warning system, in
order to reduce the tsunami-vulnerability of its coastline. The
setting up of warning systems at the international level must
therefore be viewed as an opportunity, because their
effectiveness should be reinforced by the multiplication of
seismic and sea-level data, and it should also be possible to
mutualize certain investment and operating costs between those
countries interested in creating and maintaining such a
system.
After two years of
following a wait-and-see policy, France finally seems to be
ready to assume its responsibilities. During the Lisbon session
of the ICG/NEAMTWS in late November 2007, for the first time,
France demonstrated its interest in housing a regional warning
centre and set about creating a task team responsible for
finalizing this future centre's structure and means,
establishing a calendar for its creation and evaluating its
costs. The results will be presented during the next meeting of
the ICG/NEAMTWS in Greece in October 2008.
In parallel with this initiative, the government has
decided to create a National Committee coordinated by the
Department of the Sea, responsible for setting up a national
monitoring and warning system for coastal submersions of oceanic
origin.
Your rapporteur is
pleased to see that the government is finally becoming aware of
France's need to limit the tsunami-vulnerability of its coasts,
by setting up a national warning system. In addition, the
attribution of this project to the Department of the Sea should
encourage the definition of a structure that takes into account
the needs of each basin and the determination of the each
partner's representatives.
Nevertheless, your rapporteur wonders about the financial
means that the government is ready to dedicate to these two
actions.
The absence of any
financial commitment in the proposal made in Lisbon can be
interpreted as the government's desire to question the other
member states as to their eventual contributions before making
its own proposals. However, it should be pointed out that the
delays in setting up a warning system for the Mediterranean have
resulted from this very same reluctance on the part of the
concerned countries to commit themselves financially. If
France believes that the security of its coasts demands the
creation of such a system, it will have to accept to fund at
least its initial version, without waiting for a commitment on
the part of the other countries.
Furthermore, your rapporteur would like to repeat his
worries concerning the integration of the tsunami warning system
into a multi-risk approach that threatens to bog down the
project.
Finally, your
rapporteur would like to once again point out the need to
accelerate the setting up of a warning system for the West
Indies, due to the tsunami-vulnerability of these French départements.
The project for a national monitoring and warning system must
therefore cover not only metropolitan France, but also the
overseas territories.
France's new-found enthusiasm for setting up a national
tsunami-warning system should result in its rapid
implementation. However, it is likely that the initial system
prove imperfect, due to its dependency on data transmitted by
foreign countries. Indeed, as long as the seismic and sea-level
data gathered by the North African countries remains
unavailable, the system will remain imperfect.
In order to verify that progress is made in setting up a
tsunami warning system, your rapporteur proposes that this
project be monitored. Immediately prior to the next meeting of
the ICG/NEAMTWS in October 2008, the OPECST will hold public
hearings to evaluate the progress made not only in setting up
the national warning system, but also concerning the warning
systems for the Mediterranean/northeast Atlantic, the Caribbean
and the Indian Ocean.
APPENDICES
APPENDIX 1 -
LIST OF ABBREVIATIONS
ANR
|
Agence Nationale de la Recherche ("National Research Agency")
|
BIGSETS
|
BIG Sources of Earthquake and Tsunami in South West Iberia
|
BRGM
|
Bureau de Recherches Géologiques et
Minières ("Geological and Mining Research Bureau")
|
CANCA
|
Communauté d'Agglomérations Nice-Côte
d'Azur ("Urban Community of Nice-Côte d'Azur")
|
CEA
|
Commissariat à l'Energie Atomique ("Atomic Energy Commission")
|
CETMEF
|
Centre d'Etudes Techniques Maritimes Et Fluviales
("Maritime and River Technical Research Centre")
|
CIIT
|
Centre International d'Information sur les Tsunamis
("International Tsunami Information Centre")
|
CNES
|
Centre National des Etudes Spatiales ("National Space Research Centre")
|
CNRS
|
Centre National de la Recherche Scientifique
("National Scientific Research Centre")
|
COGIC
|
Centre Opérationnel de Gestion
Interministérielle des Crises ("Operational Centre of
Interdepartmental Crisis Management")
|
IOC
|
Intergovernmental Oceanographic Commission
|
EMSC
|
European-Mediterranean Seismological Centre
|
DART
|
Deep-ocean Assessment and Reporting of Tsunamis
|
DASE
|
Département Analyse, Surveillance,
Environnement ("Analysis, Monitoring, Environment
Department")
|
DDSC
|
Direction de la Défense et de la
Sécurité Civiles ("Defense and Civil Security
Department")
|
DEWS
|
Distant Early Warning System
|
DGCID
|
Direction Générale de la Coopération
Internationale et du Développement ("Directorate General
of International Cooperation and Development")
|
DONET
|
Dense Oceanfloor Network system for Earthquakes and Tsunamis
|
DPPR
|
Direction de la Prévention des Pollutions et
des Risques ("Department of Pollution and Risk
Prevention")
|
EMSO
|
European Multidisciplinary Seas Observation
|
EOST
|
Ecole et Observatoire des Sciences de la Terre
("Earth Sciences School and Observatory")
|
ESA
|
European Space Agency
|
ESONET
|
European Seas Observatory NETwork of excellence
|
FIDES
|
Fonds d'Investissement pour le Développement
Economique et Social ("Investment Fund for Economic
and Social Development")
|
FUNVISIS
|
FUNdación Venezolana de Investigaciones
SISmologicas ("Venezuelan Foundation for Seismological
Research")
|
GAO
|
Government Accountability Office
|
GEOSS
|
Global Earth Observation System of Systems
|
GIS CURARE
|
Groupement d'Intérêt Scientifique
"Centre Universitaire de Réflexion pour une Agence des
Risques Environnementaux" ("Scientific Interest Group -
University Study Centre for an Environmental Risks
Agency")
|
GITEC
|
Genesis and Impact of Tsunamis on European Coasts
|
GITEWS
|
German-Indonesian Tsunami Early Warning System
|
GLOOS
|
Global Ocean Observing System
|
GLOSS
|
GLObal Sea level observing System
|
GMES
|
Global Monitoring of Environment and Security
|
GPRS
|
General Pocket Radio Service
|
ICG / ITSU
|
International Coordination Group for the Tsunami Warning System in the Pacific
|
IFREMER
|
Institut Français de Recherche pour
l'Exploration de la MER ("French Research Institute for
Sea Exploration")
|
IGN
|
Institut Géographique National ("National Geographic Institute")
|
IISEE
|
International Institute of Seismology and Earthquake Engineering
|
INGV
|
Istituto Nazionale di Geofisica et Vulcanologia
("National Geophysics and Vulcanology Institute")
|
INPI
|
Institut National de la Propriété
Intellectuelle ("National Intellectual Property
Institute")
|
INSU
|
Institut National des Sciences de l'Univers
("National Space Sciences Institute")
|
IPGP
|
Institut de Physique du Globe de Paris ("Paris Institute of Global Physics")
|
IRD
|
Institut de Recherche pour le Développement
("Research Institute for Development")
|
IUGG
|
International Union of Geodesy and Geophysic
|
JAMSTEC
|
Japan Agency for Marine-earth Science and TEChnology
|
JICA
|
Japon International Cooperation Agency
|
JMA
|
Japan Meteorological Agency
|
LDG
|
Laboratoire de Géophysique ("Geophysics Laboratory")
|
LEGOS
|
Laboratoire d'Etudes en Géophysique et
Océanographie Spatiales ("Research Laboratory in Spatial
Geophysics and Oceanography")
|
NEAREST
|
Integrated observations from NEAR shore sourcES of Tsunamis
|
NERIES
|
Network of Earthquake Research Institutes for Earthquake Seismology
|
NIED
|
National research Institute for Earth science and Disaster prevention
|
NOAA
|
National Oceanic and Atmospheric Administration
|
NTHMP
|
National Tsunami Hazard Mitigation Program
|
NWPTAC
|
North West Pacific Tsunami Advisory Center
|
WMO
|
World Meteorological Organization
|
UN
|
United Nations
|
OVSG
|
Observatoire Vulcanologique et Sismologique de la
Guadeloupe ("Vulcanological and Seismological
Observatory of Guadeloupe")
|
OVSM
|
Observatoire Vulcanologique et Sismologique de la Martinique
("Vulcanological and Seismological Observatory of Martinique")
|
PSS
|
Plan de Secours Spécialisé ("Specialized Emergency-Assistance Plan")
|
PTWC
|
Pacific Tsunami Warning Center
|
RATCOM
|
Réseau d'Alerte aux Tsunamis et CÔtiers
en Méditerranée ("Tsunami Warning Network for the
Mediterranean Coasts")
|
RFO
|
Réseau France Outremer ("Overseas France Network")
|
RONIM
|
Réseau d'Observatoires du NIveau des Mers ("Network of Sea-Level Observatories")
|
ROSAME
|
Réseau d'Observation Subantarctique et
Antarctique du niveau de la Mer ("Subantarctic and
Antarctic Sea-Level Observation Network")
|
SAFER
|
Seismic eArly warning For EuRope
|
SEAHELLARC
|
SEismic risk Assessment and mitigation scenarios in Western HELLenic ARC
|
SHOM
|
Service Hydrographique et Océanographique de
la Marine ("Hydrography and Oceanography Department
of the Navy")
|
ISDR
|
International Strategy for Disaster Reduction
|
GTS
|
Global Telecommunication System
|
SPANET
|
South PAcific broadband seismic NETwork
|
ISS
|
International Surveillance System
|
CNTBT
|
Comprehensive Nuclear-Test-Ban Treaty
|
TRANSFER
|
Tsunami Risk ANd Strategies For the European Region
|
TREMORS
|
Tsunami Risk Evaluation through seismic MOment from a Real-time System
|
TWO
|
Tsunami Warning and Observations
|
UNESCO
|
United Nations Educational, Scientific and Cultural Organization
|
VSAT
|
Very Small Aperture Telecommunications
|
WC-ATWC
|
West Coast - Alaska Tsunami Warning Center
|
APPENDIX 2 -
LIST OF PERSONS INTERVIEWED
· Serge ALLAIN, the Navy's Hydrographic and Oceanograhic Department
· Philippe AUDEBERT, Head Clerk, Major Risk Management Office, Ministry of the Interior
· Simon BABRE, Principal Private Secretary to the
Director of Political, Administrative and Financial Affaires,
Junior Minister's Office for the Overseas Territories
· Patricio BERNAL, Assistant Director of the Intergovernmental Oceanographic Commission
· Pascal BERNARD, Institut de Physique du Globe de Paris ("Paris Institute of Global Physics")
· Catherine BERSANI, Chief Inspector for Equipment
· Georges BOUDON, Institut de Physique du Globe de Paris ("Paris Institute of Global Physics")
· Pierre BRIOLE, Director of Research at the CNRS
("National Scientific Research Centre"), Ecole Normale
Supérieure
· François BRUN,
Assistant Director, Institut Géographique National ("National
Geographic Institute")
· Geoffroy CAUDE, Director, Centre d'Etudes Techniques
Maritimes et Fluviales ("Maritime and River Technical Research
Centre")
· Adolphe COLRAT,
Director of Political, Administrative and Financial Affaires,
Junior Minister's Office for the Overseas Territories
· Pierre COCHONAT, Programme and Strategy Department,
IFREMER ("French Research Institute for Sea Exploration")
· Vincent COURTILLOT, Director, Institut de Physique du
Globe de Paris ("Paris Institute of Global Physics")
· Bertrand DUCROS, Head of the Civil Security Mission,
Junior Minister's Office for the Overseas Territories
· Bruno FEIGNIER, Director, Analysis, Monitoring, Environment Department
· René FEUNTEUN, Pollution and Risk Prevention
Department, Ministry of Ecology and Sustainable Development
· François GÉRARD, President of
the National Committee of the Intergovernmental Oceanographic
Commission
· Bruno
GOFFÉ, Centre National de la Recherche Scientifique ("National
Scientific Research Centre")
· Xavier de la GORCE, General Secretary of the Department of the Sea
· Elie JARMACHE, Department of the Sea
· Anne LE FRIANT, Institut de Physique du Globe de Paris ("Paris Institute of Global Physics")
· Dominique LE QUÉAU, Director, Institut National des
Sciences de l'Univers ("National Space Sciences Institute")
· Joël L'HER, Centre d'Etudes
Techniques Maritimes et Fluviales ("Maritime and River Technical
Research Centre")
·
Philippe LOGNONNÉ, Researcher, Institut de Physique du Globe de
Paris ("Paris Institute of Global Physics")
· Jean-Claude MALLET, former Post-Tsunami Interministerial Delegate
· Jean-Pierre MAC VEIGH, Associate Director for the
French Overseas Territories, Météo France (French Meteorological
Service)
· Hormoz
MODARESSI, Bureau de Recherches Géologiques et Minières
("Geological and Mining Research Bureau")
· Denis MOUSSON, Fire and Emergency Services Department, Val d'Oise
· Rodrigo PEDREROS, Bureau de Recherches Géologiques et
Minières ("Geological and Mining Research Bureau")
· Jean-Claude PETIT, Director of Programmes, Atomic Energy Commission
· Philippe SABOURAULT, Pollution and Risk Prevention
Department, Ministry of Ecology and Sustainable Development
· Lieutenant Colonel SARRON, Head of the Interministerial Crisis Management Centre
· François SCHINDELE, Senior Expert on Tsunamis,
Commissariat à l'Energie Atomique ("Atomic Energy Commission")
· Michel SEGARD, Pollution
and Risk Prevention Department, Ministry of Ecology and
Sustainable Development
· Eléonore STUTZMANN, Director, GEOSCOPE
· Monique TERRIER, Bureau de Recherches Géologiques et
Minières ("Geological and Mining Research Bureau")
· Jacques VARET, Director of Prospecting, Bureau de
Recherches Géologiques et Minières ("Geological and Mining
Research Bureau")
· Guy WOPPELMANN, University of La Rochelle
· Laurent BIGOT, Principal Private Secretary to the Prefect
· Jean-Marc BONNET, Director of the Inter-regional
Antilles-French Guiana Department of Météo France (French
Meteorological Service)
· Philippe COVA, Chief of Staff for the West Indies
· Yves DASSONVILLE, Prefect
· Raymond JEAN-NOEL, Head of the Interministerial
Department of Civil, Economic, Defense and Civil-Protection
Affairs
· Claude LISE, Senator of Martinique
· Lieutenant Colonel Vincent PALCY, Fire and Emergency Services Department
· Max REYAL, Météo France (French Meteorological Service)
· Yves SIDIBE, Director of Infrastructure and Water at the Departmental Council of Martinique
· Narcisse ZAHIBO, Senior Lecturer, University of the West Indies and French Guiana
· Michel BACOU, Project Head for the "Natural Risks" Mission, Regional Environmental Department
· Vincent CHERY, Departmental Head, Force 06
· Yannick DORGIGNE, Project Head, Policy and Monitoring
Committee for Seismic Risk, Environmental Department, Greater
Nice/Côte d'Azur
· Anne DESCHAMPS, Director of Research, CNRS ("National Scientific Research Centre")
· Anne-Marie DUVAL, Centre d'Etudes Techniques de l'Equipement ("Technical Equipment-Research Centre")
· Jean-François FABRE, Director of Aquatic Environments
and the "Bay Contract", Environmental Department, Greater
Nice/Côte d'Azur
· Yannick FERRAND, Engineer, Department of Urban-Risk Prevention, City of Nice
· Stéphane GAFFET, Researcher, CNRS ("National Scientific Research Centre")
· Jean-Marc GUERIN, Director, Ecology and Sustainable
Development Department, Departmental Council of the
Alpes-Maritimes
· Marc LAFAURIE, Deputy Mayor, Vice President of Greater Nice/Côte d'Azur
· Jessica LE PUTH, Engineer, GEOAZUR
· William MARTIN, Interministerial Director of Defense
and Civil Protection, Prefecture of the Alpes-Maritimes
· Josiane NOEL, Engineer, Department of Urban-Risk Prevention, City of Nice
· Christophe PREZ, Project Head for the cabinet of Marc LAFAURIE
· Yves PRUFER, Environmental Director, Greater Nice/Côte d'Azur
· Monique RAGAZZI-CAZON, Assistant Director, Department
of Strategy, Sustainable Development and Nature, Departmental
Council of the Alpes-Maritimes
· Claire-Anne REIX, Project Head, GMES (Global Monitoring of
Environment and Security), Thalès Alenia Space
· Olivier SARDOU, Engineer, GIS CURARE ("Scientific
Interest Group - University Study Centre for an Environmental
Risks Agency")
· Jean
VIRIEUX, Director, GIS CURARE ("Scientific Interest Group -
University Study Centre for an Environmental Risks Agency")
· Christine BERNOT, Director of Scientific and
Technical Projects, General Directorate for Enterprises,
European Commission
· Peter BILLING, Civil Protection Service, General Directorate for the Environment, European Commission
· Karen FABBRI, General Directorate for Research, European Commission
· Jean-Paul MALINGREAU, Service Head, Joint Research Centre
· Josiane MASSON, Director of Scientific and Technical
Projects, General Directorate for Enterprises, European
Commission
· Luc FAATAU, Minister of Property and Development
· Yves HERMANN-AUCLAIR, Assystem
· Pascal MAINGUY, Director of Civil Protection
· Dominique REYMOND, Director of LDG/Pamatai ("Geophysics Laboratory")
· Alexis ROSTAND, Captain, Marines and Naval Aeronautics
· Benoît TREVISANI, Principal Private Secretary to the High Commissioner
· Cheryl L. ADERSON, Director
Hazard, Climate & Environment Program, Social Science
Research Institute, University of Hawaii
· Leighton AH COOK, Branch Chief - Training, Education and Information, Hawaii State Civil Defense
· Jeanne BRANCH JOHNSTON, Earthquake and Tsunami Program Planner, Hawaii State Civil Defense
· Kwok Fai CHEUNG, Chair and Professor - Dept of Ocean
& Resources Engineering, Department of Ocean & Resources
Engineering
· Delores CLARK, Public Affairs Officer, National Oceanic and Atmospheric Administration
· Walter C. DUDLEY, Professor, Kalakaua Marine Education Center, University of Hawaï
· Ken GILBERT, City and County of Honolulu
· Harry KIM, Mayor of Hilo
· Laura S.L. KONG, Director, International Tsunami Information Center
· Charles McCREERY, Director of the National Weather Service, Pacific Tsunami Warning Center
· Ed TEIXEIRA, Deputy Director, Hawaii State Civil Defense
· LTC Stanley E. TOY, Chief of Operations, Joint Task Force
· Stuart WEINSTEIN, Pacific Tsunami Warning Center
· Brian S. YANAGI, Disaster Management Specialist, International Tsunami Information Center
· Yushiro FUJII, International Institute of Seismology and Earthquake Engineering
· Yohei HASEGAWA, Chief Researcher, Meteorological Research Institute
· Yutaka HAYASHI, Senior Researcher, Meteorological Research Institute
· Shigeshi HORIUSHI, National Research Institute for Earth Science and Disaster Prevention
· Nobuo HURUKAWA, Director, International Institute of Seismology and Earthquake Engineering
· Hidemi ITO, Meteorological Research Institute
· Osamu KAMIGAICHI, Senior Coordinator for
International Earthquake and Tsunami Information, Japan
Meteorological Agency
·
Kazushige OBARA, Earthquake Research Department, National
Research Institute for Earth Science and Disaster Prevention
· Yasunori OTSUBO, Tokyo Town Council
· Bunichiro SHIBAZAKI, Chief Seismologist,
International Institute of Seismology and Earthquake Engineering
· Hiromi TAKAYAMA, Meteorological Research Institute
· Toshio WATANABE, Tokyo Town Council
· YAMASAKI, Fire and Disaster Management Agency
· Dr. Alessandro AMATO, Director of the seismic
surveillance network at the Instituto Nazionale di Geofisica e
Vulcanologia ("National Geophysics and Vulcanology Institute")
· Mauro DOLCE, Civil Protection Service
· Professor Stefano TINTI, Instituto Nazionale di
Geofisica e Vulcanologia ("National Geophysics and Vulcanology
Institute")
* 1
"Les techniques de prévision et de prévention des
risques naturels : séismes et mouvements de terrain", report
no. 261 (Senate) and no. 2017 (National Assembly) by Mr.
Christian Kert, Deputy, on behalf of the Parliamentary Office
for the Evaluation of Scientific and Technological Choices
(1995).
* 2 "Les techniques de prévision et de prévention des risques naturels en France", report
no. 312 (Senate) and no. 1540 (National Assembly) by Mr.
Christian Kert, Deputy, on behalf of the Parliamentary Office
for the Evaluation of Scientific and Technological Choices
(1999).
* 3 A
discontinuity or fracture in the earth's crust, showing
evidence of relative movement between the two blocks of rock
separated by the fault.
* 4 Wave length is the distance between two successive crests of a periodic wave.
* 5 The
Lesser Antilles are a string of small islands of volcanic or
calcareous origin, which form an arc stretching from the
Virgin Islands east of Puerto Rico to Grenada to the south.
* 6 The
NOAA is a federal agency dependent on the United States
Department of Commerce. Its writ extends to all issues relative
to the state of the oceans and atmosphere. In particular, it is
in charge of evaluating the risk and limiting the impact of
tsunamis.
* 7 In which case, the "only" risk run is that of issuing a false warning.
* 8 Seismometers can also be used to detect volcanic eruptions and landslides.
* 9 Since
its creation, the ICG/Pacific group has been responsible for
making recommendations with respect to the prevention
programmes set up by member states whose coasts are threatened
by tsunamis and to coordinate these various programmes. To meet
these objectives, the group is invited to meet every two years
or so in one of the member states. The ICG/Pacific assesses both
the measurements taken and any inadequacies observed, and
establishes an action programme to solve the latter. If
necessary, working groups are created.
* 10 The
WC-ATWC and NWPTAC will be considered in detail in the
following sections on the American model and the Japanese model,
respectively.
* 11 West Coast/Alaska Tsunami Warning Center.
* 12 Assessing a country's capacity to set up a tsunami warning system.
* 13 For this zone, both PTWC and JMA are responsible for issuing warnings.
* 14 The West Coast/Alaska Tsunami Warning Center (WC/ATWC).
* 15 This zone is located off the coasts of Washington, Oregon and California.
* 16 Out of an eventual 500 sites.
* 17 National Research Institute for Earth Science and Disaster Prevention.
* 18 Most are multi-risk structures, because Japan must also confront cyclonal swells and typhoons.
* 19 Japan Agency for Marine-Earth Science and Technology, which corresponds to France's IFREMER.
* 20 Dense Oceanfloor Network System for Earthquakes and Tsunamis.
* 21International Institute of Seismology and Earthquake Engineering.
* 22 Japon International Cooperation Agency.
* 23 The
Département Analyse, Surveillance, Environnement
("Department of Analysis, Surveillance and the Environment") of
CEA ("Atomic Energy Commissariat").
* 24 This trademark was first registered with the INPI in 1994 and was renewed in 2004 for a further 10 years.
* 25 This
plan defines the missions and responsibilities of all
concerned services in the event of a tsunami warning and
establishes the steps to be taken to evacuate the population, if
need be.
* 26 Experience
has shown that as soon as a disaster is announced, the
telephone network is immediately saturated. In addition,
Papeete's "Postal and Telecommunications Service" is located on
the shoreline: it would be put out of service - and the area's
telephone communications would be interrupted - by 1.5 metre or
higher waves.
* 27 In particular, UNESCO via the IOC.
* 28 The
varying terminology used by the three new intergovernmental
groups can lead to some confusion. For example, in the Indian
Ocean, the term used is "Regional Tsunami Watch Provider",
while the Caribbean zone has up until now borrowed the
ICG/Pacific term: "regional tsunami warning centre". According
to the information gathered by your rapporteur, regardless of
these formal differences, each regional centre is supposed to
carry out the same missions for its geographic zone: issue a
message indicating the source of origin, the possibility of a
tsunami having been provoked, and (if affirmative) the estimated
time of arrival and the regions liable to be affected. However,
the countries remain responsible for the actual warning (in
terms of informing and protecting the population).
* 29 Responsible
for federating all observation resources, in order to better
understand the climate and the environment and help predict
natural disasters. Its marine component is the Global Sea
Level Observing System (GLOSS).
* 30 More
bulky seismic data is transmitted via a different system [in
general, via the Very Small Aperture Terminal (VSAT)
network, which uses geostationary satellites, or the more robust
VAST system; the General Pocket Radio Service (GPRS) and
Internet play a secondary, backup role, due to their being very
"unwieldy"].
* 31 This project enjoys €1.3 million in funding and gathers together 7 partners.
* 32 This project enjoys €3.6 million in funding and gathers together 29 partners.
* 33 The
objective of the Antares project is to detect and study
very high-energy cosmic neutrinos in the Mediterranean. Cosmic
neutrinos are elementary particles that pass almost undisturbed
through matter and can therefore travel great distances in the
Universe without being absorbed by the interplanetary mediums.
Used in addition to electromagnetic radiation, they represent an
exceptional means of studying distant corners of the universe.
They can also provide us with indirect information on the nature
of the universe's hidden mass. Due to their very weak
interactivity with matter, very large detectors isolated from
cosmic radiation must be used. Indeed, cosmic rays are
constantly bombarding the Earth's surface, creating significant
background noise. For this reason, the sea floor, which is
naturally protected from such radiation by its depth, represents
an ideal environment for the detection of neutrinos. In the
Antares experiment, a thousand photodetectors are immerged
at a depth of 2,400 m in the Mediterranean on a site located
south of the island of Porquerolles (the Var département) chosen
for the quality of its water. These sensitive photodetectors
directed towards the ground will capture the light emitted by
the neutrino products that have passed through the Earth and
interact with it near the sea bottom. This arrangement will
allow the detectors to study the southern hemispheric sky, which
includes the centre of the galaxy, the location of several
phenomena of intense energy. These large systems can
therefore be considered "neutrino telescopes".
* 34 Following
the tsunami of 26 December 2004, Germany very quickly
manifested a desire to come to the aid of those countries
devastated by the tsunami and on 13 January 2005 decided to set
up the German Indonesian Tsunami Early Warning System (GITEWS).
This project, directed by the Ministry of Education and Research
and allocated €45 million in funding, should allow for rapid,
reliable warnings; it relies on a network of earth observations
(seismic and geodesic sensors), sea observations (tide gauges
and sea-based pressure sensors), a precise bathymetry of the
regions to be protected, computer simulations and a warning
centre in charge of receiving and processing the data and, if
need be, issuing warnings. This regional tsunami warning centre
is supposed to integrate the warning system for the Indian Ocean
managed by the IOC. The German engineers have developed a
computer program capable of determining the location, magnitude
and depth of a strong earthquake within 4 minutes of its first
manifestation.
* 35 Information
(rather than warning) messages are issued, because the data
available to these two centres is not sufficient to allow
them to issue reliable warning bulletins. These two centres
currently base their analysis on the data transmitted by 30
seismic stations, 41 tide gauges and one DART buoy installed off
the coast of Thailand.
* 36 As
has already been pointed out, the terminology used often
differs according to region. The terminology chosen for the
Indian Ocean zone is meant to avoid offending national
susceptibilities by maintaining a balance between the ICG member
states.
* 37 «La Fundación Venezolana de Investigaciones Sismológica»s (FUNVISIS).
* 38 For example, it does not function 24 hours a day, 7 days a week.
* 39 Initially,
these tide gauges must be capable of sending a signal every
minute when they are located more than 1 hour (or 100 km)
from a tsunami-generating source, with eventually messages being
sent every 15 seconds.
* 40 The
three tsunamis generated after that of 26 December 2004 are the
tsunamis of 28 March 2005, 17 July 2006 and 12 September
2007, each of which claimed victims. This has put into
perspective the "exceptional" character of the Sumatra tsunami,
which certain persons have used to justify the absence of a
warning system in this region.
* 41 Taking into account the Principality of Monaco.
* 42 These
are pre-established criteria for issuing a warning. In
Polynesia, 4 warning levels have been established, based on the
magnitude of the earthquake, the distance of the source and the
zones liable to be affected (distinguishing the Marquesas
Islands from the rest of French Polynesia).
* 43 IPGP
is also involved in the tsunami warning systems for the Pacific
and Mediterranean zones, via the GEOSCOPE stations set up in
these regions.
* 44 Among
the 28 seismic stations, 18 are managed by IPGP, 6 are managed
by the Ecole et Observatoire des Sciences de la Terre (EOST)
in Strasbourg, 2 are managed by CEA/DASE, and 2 are
co-managed with the United States Geological Survey (USGS).
Station maintenance is also carried out in collaboration with
several institutes [the EOST, the Institut de Recherche pour le
Developement (IRD), CEA/DASE, the Comprehensive Test-Ban Treaty
Organization (CTBTO), the Centre National d'Etudes Spatiales
(CNES), the USGS, and local universities housing stations].
* 45 The data-transmission time is less than 1 minute.
* 46 The
Djibouti station was made to function in real-time within
the framework of the Comprehensive Nuclear-Test-Ban Treaty.
However, its data is not transmitted directly to IPGP, but
rather to the Vienna International Data Centre.
* 47 Météo
France, IPGP, EOST, SHOM, the Direction Départementale de
l'Equipement de Mayotte ("Departmental Facilities Office for
Mayotte"), CNRS/INSU/LEGOS, CEA/DASE, the Institut Paul Emile
Victor, the Administration des Terres Australes et Antarctiques
Françaises ("French Southern and Antarctic Lands
Department"), the National Committee of the IOC.
* 48 Concretely:
the Transmet message switch, the Retim system for
meteorological data transmission by satellite, and the Synergie
weather-forecasting system.
* 49 French Polynesia was not included in the study.
* 50 An
earthquake with a known maximum historical magnitude, to which
0.5 degrees of magnitude is added to compensate for any
uncertainties regarding the seismic data.
* 51 The
GIS CURARE initially consisted of 5 members: Nice Sophia
Antipolis University, Pierre and Marie Curie University, the
CNRS, the Institut de Recherche et Developement (IRD), and the
private company ACRI ST. BRGM, IFREMER and SHOM later
joined this project, as did the Conservatoire National des Arts
et Métiers ("National School of Engineering and Technology").
* 52 The
two other themes concerned gravitational instabilities and
landslides in the High Tinée Valley and the estimation of
strong movements during major coastal earthquakes.
* 53 However,
your rapporteur would like to point out that no reliable
inundation map can currently be produced for the West Indies,
insofar as the tsunami models suffer from the absence of a
precise bathymetry for the zone extending from 0 to 200 m all
around the French West Indies.
* 54 Météo
France has received €1,472 million from the Directorate General
for International Cooperation and Development, to be
distributed among its various partners; CEA has directly
received €444,000 for the updating of its seismic stations in
Indonesia; finally, the National Committee of the IOC has also
directly received €50,000.
* 55 Those of La Réunion and Canberra.
* 56 France's
overseas départements are exposed to a host of natural
hazards besides geophysical risks such as cyclones or those
linked to heavy rains such as landslides and inundations.
However, considering the subject of this study, your rapporteur
has chosen to focus his attention on those natural hazards
liable to generate a tsunami: namely, earthquakes and collapsing
volcanoes.
* 57Martinique's
last devastating earthquake dates back to 1839 and statistics
on earthquake occurrency suggest that the next earthquake is
imminent.
* 58 The
tsunami of 13 July 2003 caused by the collapsing dome of the
Montserrat volcano caused some damage in Guadeloupe and
served as a reminder of this island's vulnerability to tsunamis.
Therefore, in 2004, the Ministry of Overseas Territories
financed the installation of 4 tide gauges to continuously
monitor variations in sea level, in order to analyze the site
effects and propagation times of an eventual tsunami on
Guadeloupe's coasts.
* 59 As
has already been mentioned, the regional warning message will
rely on a decision matrix that can nevertheless prove to be
somewhat unsuitable at the local level. For instance, Antibes is
a more tsunami-vulnerable zone than Nice due to its relief
and bathymetry. Likewise, harbours are more vulnerable to
tsunamis due to the currents and eddies they produce.
* 60 At
least regional and tele-tsunamis. To handle local tsunamis,
the warning system must be automated via
automatically-activated sirens.
* 61 For regional-tsunami warnings; in other words, with a reaction time of at least a half hour.
* 62 These
costs could be partially mutualized within the framework of a
yet-to-be-defined European funding programme.
* 63 The
Ministry of Ecology and Sustainable Development, the
Ministry of the Interior and the Overseas Territories, and the
Ministry of Foreign Affairs.
* 64 It
would seem that at least three warning centres will be
created: one for tsunamis from the Atlantic, one for tsunamis
from the eastern Mediterranean and one for tsunamis from the
western Mediterranean.
* 65 This
team will include all countries concerned by this proposal, the
Steering Committee of the ICG/NEAMTWS and the chairmen of
the 4 working groups, as well as representatives of other
organizations, such as the European Commission, the World
Meteorological Organization and the European-Mediterranean
Seismological Centre. It will be co-presided over by France and
the United Kingdom.
* 66 In
this case, the warning system for the Loyalty Islands will rely
on educating the population, which must learn to automatically
quit the coast for higher land should it perceive any signs
of a strong earthquake having occurred.
* 67 This
zone also includes the island of Futuna, in the area of
which a tsunami-generating earthquake could occur. However, as
in the case of a tsunami-generating earthquake occurring in the
area of the Loyalty Islands, the nearby earthquake would have to
be immediately detected in order to warn the island's
population in time, due to the very short delay between the
earthquake's occurrence and the tsunami arrival.
* 68 Australia
plans on installing a tide gauge on Tagia Island, as well as a
tsunamimeter north of New Caledonia, in order to monitor
tsunamis from zone 1. To monitor tsunamis from zone 6, the tide
gauge that already exists in Nukualofa and the two new tide
gauges Australia plans to install in Raoul Island and Norfolk
will suffice. Finally, zone 4 (southern Fiji) is less dangerous,
due to the fault zone's orientation.
* 69 Coastal submersions of marine origin include: storm surges, swells, rising sea levels and tsunamis.
* 70 Extraplac
is the French programme to extend the continental shelf. The
United Nations Convention on the Law of the Sea applies to
the world's oceans: the use of oceanic resources, navigation,
prospecting and sea-bed mining. This convention authorizes,
under certain conditions, coastal countries to extend the marine
zones under their jurisdiction beyond the limits of their
exclusive economic zones. Extension requests will be examined by
a special UN commission before 13 May 2009. France has
therefore decided, via the Extraplac project, to prepare its
requests for all potential extension zones.
* 71 Sea-level monitoring network.
* 72 Laboratoire
d'Etudes en Géophysique et Océanographie Spatiales
("Space-Based Geophysics and Oceanography Research Laboratory").
* 73 Réseau
d'Observation Subantarctique et Antarctique du niveau de la MEr
("Subantarctic and Antarctic Sea-Level Observation Network").
* 74 Also a research professor at the University of La Rochelle.
* 75 In other words, using the same altitude-based system of reference.
* 76 Nearly 60 local governments are involved in La Réunion's specialized emergency plan.
* 77 By
focusing on not only its relatively low occurence, but also the
serious consequences it can have for the coastal population.
* 78 The candidate countries are: Italy, the United Kingdom, Portugal, Greece, Turkey, Spain and France.
* 79 According
to the information obtained by your rapporteur, those in
Fort-de-France and Pointe-à-Pitre are already equipped with
the necessary outlets for real-time data transmission.
* 80 Centre d'Etudes Maritimes Et Fluviales ("Sea and River Research Centre").
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