ATTENUATION RELATIONS OF STRONG MOTION IN JAPAN USINGSITE CLASSIFICATION BASED ON PREDOMINANT PERIOD

摘要

A spectral acceleration attenuation model for Japan is presented. The data set includes a very largenumber of strong ground motion records up to the end of 2003. Site class terms, instead of individualsite correction terms, are used based on a recent study on site classification for strong motionrecording stations in Japan. By using site class terms, tectonic source type effects are identified andaccounted in the present model. Effects of faulting mechanism for crustal earthquakes are alsoaccounted for. For crustal and interface earthquakes, a simple form of attenuation model is able tocapture the main strong motion characteristics and achieves unbiased estimates. For subduction slabevents, a simple distance modification factor is employed to achieve plausible and unbiasedprediction. Effects of source depth, tectonic source type, and faulting mechanism for crustalearthquakes are significant.