Annualized and Scenario Earthquake Loss Estimations for California

Abstract

We update annualized and scenario earthquake loss estimations for California using HAZUS, a loss estimation tool developed by the Federal Emergency Management Agency, and evaluate the effects of changes in input ground motions over the last decade on estimated earthquake losses. Our estimated statewide average earthquake loss to building stock from shaking is approximately $2.8 billion per year, with 32% of it occurring in Los Angeles County and 23% in the San Francisco-Oakland-Fremont metropolitan statistical area. This estimate reflects a 25% to 28% reduction because of changes in input ground motions. Scenario results indicate a 28% to 63% reduction in estimated building economic losses because of changes in input ground motions. Changes in input ground motions are mainly attributed to the use of next generation attenuation relations and, to a lesser extent, to updated earthquake source models and differing approaches for incorporating near-surface site effects.