LOSSES AFTER QUAKES

Front. Built Environ., 13 June 2017 | https://doi.org/10.3389/fbuil.2017.00030

Losses Associated with Secondary Effects in Earthquakes

James E. Daniell*, Andreas M. Schaefer and Friedemann Wenzel

• Geophysical Institute, Center for Disaster Management and Risk Reduction Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany
• http://journal.frontiersin.org/article/10.3389/fbuil.2017.00030/full#B46

The number of earthquakes with high damage and high losses has been limited to around 100 events since 1900. Looking at historical losses from 1900 onward, we see that around 100 key earthquakes (or around 1% of damaging earthquakes) have caused around 93% of fatalities globally. What is indeed interesting about this statistic is that within these events, secondary effects have played a major role, causing around 40% of economic losses and fatalities as compared to shaking effects. Disaggregation of secondary effect economic losses and fatalities demonstrating the relative influence of historical losses from direct earthquake shaking in comparison to tsunami, fire, landslides, liquefaction, fault rupture, and other type losses is important if we are to understand the key causes post-earthquake. The trends and major event impacts of secondary effects are explored in terms of their historic impact as well as looking to improved ways to disaggregate them through two case studies of the Tohoku 2011 event for earthquake, tsunami, liquefaction, fire, and the nuclear impact; as well as the Chilean 1960 earthquake and tsunami event.

Introduction

Disaggregation of secondary effect economic losses and fatalities demonstrating the relative influence of historical losses from direct earthquake shaking in comparison to tsunami, fire, landslides, liquefactions, fault rupture, and other type losses is important if we are to understand the key causes post-earthquake.

Existing studies have attempted to examine the key causes without putting dollar values to the losses, e.g., Bird and Bommer (2004) studied 50 earthquakes between 1980 and 2003 for all secondary effect types, Keefer (1984) and Rodrıguez et al. (1999) for landslide losses, and NGDC/NOAA (2010) for tsunami losses. Although most historical losses have been earthquake shaking related, the influence of the 2011 Tohoku earthquake has changed the historical percentages significantly for tsunami, just as the 1995 Kobe and 2011 Christchurch earthquakes have with regard to liquefaction. Liquefaction has occurred in many earthquakes but this is also difficult to disaggregate for older historical earthquakes. Fire in 1906 San Francisco and 1923 Great Kanto caused significant losses, but since then, important losses have also occurred in many earthquakes. Landslide losses in Haiyuan 1920, Ancash 1970, El Salvador 2001, Kashmir 2005, and Sichuan 2008 were dominant in the database, with many other incidents causing minor damages. Quite often for smaller events, landslides deliver a great amount of the clean-up cost, and indeed sectoral losses. Infrastructure, such as roads, is particularly vulnerable to landslides and secondary effects, often causing much of the damage (i.e., Kaikoura 2016).

This paper sets out to examine the percentage of socioeconomic losses of the secondary effects as compared to primary effects of earthquakes. It also sets out to examine the way in which secondary losses have been counted in past disasters by examining Tohoku 2011 and Chile 1960 in a fact-finding approach. (...)