[S07-1] Amplification of ground motions and GMPEs

[S07-1-05] Regional Difference of Ground Motion for Shallow Crustal Earthquake in Taiwan and California

^○Shu-Hsien Chao, Chiao-Chu Hsu (National Center for Research on Earthquake Engineering)

While performing the probability seismic hazard analysis, one most important question is if the ground motion model developed for one region can be used directly to another region. In order to answer this question, we should confirm if there is a significant difference of ground motion between two regions at first stage, identify the origin of the difference in second stage, and quantify the difference for different ground motion scenario in third stage. Generally, it can be evaluated by different approaches including (1) comparison of available ground motion models; (2) analysis of variance for ground motion database; (3) verification of ground motion model relative to regional data; (4) development of ground motion model with basic function form for two regions. In this study we discuss the regional difference of ground motion for shallow crustal earthquake in Taiwan and California as a case study by developing the ground motion model with basic function form for two regions. We compare the spectral shape, magnitude scaling, depth scaling, distance scaling, style of faulting factors, linear and nonlinear site effects for two regions to identify the origins of the difference. The ground motion difference is quantified by evaluating the ground motion ratio between two regions for different ground motion scenario. This ground motion ratio can be used to adjust other ground motion model from one region to another region for the probability seismic hazard analysis.