ATTENUATION MODELS FOR RESPONSE SPECTRA DERIVED FROM JAPANESE STRONG-MOTION RECORDS ACCOUNTING FOR TECTONIC SOURCE TYPES

摘要

A spectral acceleration attenuation model for Japan is presented. It accounts for effects of tectonic source type and the faulting mechanisms for crustal earthquakes. Site class terms, instead of individual site correction terms, are used based on a recent study on site classification for strong motion recording stations in Japan. By using site class terms, source type effects are identified. For crustal and interface earthquakes, a simple form of attenuation model is able to capture the main strong motion characteristics and achieve unbiased estimates. For subduction slab events, a simple distance modification factor is employed to achieve plausible and unbiased prediction. Effects of source depth, tectonic source type, and faulting mechanisms for crustal earthquakes are significant.