NEHRP Clearinghouse
- Title
- Estimating Casualties for Large Earthquakes Worldwide Using an Empirical Approach.
- File
- PB2009116205.pdf
- Author(s)
- Jaiswal, K.; Wald, D. J.; Hearne, M.
- Source
- January 2009, 84 p.
- Identifying Number(s)
- USGS-OFR-2009-1136
- Abstract
- We studied the earthquake mortality rates for more than 4,500 worldwide earthquakes since 1973 and developed an empirical country- and region-specific earthquake vulnerability model to be used as a candidate for post-earthquake fatality estimation by the U.S. Geological Surveys Prompt Assessment of Global Earthquakes for Response (PAGER) system. Earthquake fatality rate is defined as the ratio of the total number of shaking-related fatalities to the total population exposed at a given shaking intensity (in terms of Modified-Mercalli (MM) shaking intensity scale). An atlas of global Shakemaps developed for PAGER project (Allen and others, 2008) and the Landscan 2006 population database developed by Oak Ridge National Laboratory (Dobson and others, 2000; Bhaduri and others, 2002) provides global hazard and population exposure information which are necessary for the development of fatality rate. Earthquake fatality rate function is expressed in terms of a two-parameter lognormal cumulative distribution function. The objective function (norm) is defined in such a way that we minimize the residual error in hindcasting past earthquake fatalities. The earthquake fatality rate is based on past fatal earthquakes (earthquakes causing one or more deaths) in individual countries where at least four fatal earthquakes occurred during the catalog period. All earthquakes that have occurred since 1973 (fatal or non-fatal) were included in order to constrain the fatality rates for future estimations. Only a few dozen countries have experienced four or more fatal earthquakes since 1973; hence, we needed a procedure to derive regional fatality rates for countries that had not had enough fatal earthquakes during the catalog period. We propose a new global regionalization scheme based on idealization of countries that are expected to have similar susceptibility to future earthquake losses given the existing building stock, its vulnerability, and other socio-economic characteristics.
- Keywords
- Earthquake vulnerability model; Worldwide; Prompt Assessment of Global Earthquakes for Response (PAGER); Estimating casualties; US Geological Survey (USGS); Empirical approach; Earthquakes