Estimation of seismic hazard potential in Taiwan based on ShakeMaps

Abstract

A catalog of 2,044 shallow earthquakes occurring from 1900 to 2010 with Mw magnitudes ranging from 5.0 to 8.2 and 11 disastrous earthquakes occurring from 1683 to 1899 are used to estimate the seismic hazard potential in Taiwan using ShakeMaps. The ShakeMaps show that a high Modified Mercalli Intensity (MMI) greater than VIII in the Taipei basin, Nanao, Ilan plain, Chianan plains, Hualien and Taitung Longitudinal Valley is all related to the large damaging earthquakes occurring in these areas. Relatively low seismic hazard potential in Changhua area with a peak ground acceleration lower than 200 gal based on data from 1900 to 2010 may be misleading, considering the occurrence of damaging historical earthquakes before 1900 and the presence of Changhua fault in the area. In addition, based on seismic intensity probabilities for the 16 selected major cities in Taiwan over 10-, 30- and 50-year periods corresponding to a MMI greater than VI, VII and VIII, the results indicate that Chiayi, Yunlin, Ilan and Hualien have the highest possibilities of shaking hazards, while Taipei, New Taipei and Taoyuan have lower possibilities, and Kaohsiung and Pingtung have the lowest. Specifically, for the largest cities, Taipei and New Taipei, the probabilities of experiencing moderate damaging earthquake shaking within a 10-year period are 13 and 24 %, respectively.