Empirical model for estimating Fourier amplitude spectra of ground acceleration in Taiwan region

A collection of ground-motion recordings (1070 acceleration records) of mod erate (5.1 less than or equal to M-L less than or equal to 6.5) earthquakes obtained during the execution of the Taiwan Strong Motion Instrumentation Program (TSMIP) since 1991 was used to study source scaling model and atten uation relations for a wide range of earthquake magnitudes and distances an d to verify the models developed recently for the Taiwan region. The result s of the analysis reveal that the acceleration spectra of the most signific ant part of the records, starting from S-wave arrival, can be modelled accu rately using the Prune's omega-squared source model with magnitude-dependen t stress parameter Delta sigma, that should be determined using the recentl y proposed regional relationships between magnitude (M-L) and seismic momen t (M-o) and between M-o and Delta sigma. The anelastic attenuation Q of spe ctral amplitudes with distance may be described as Q = 225 f(1.1) both for deep (depth more than 35 km) and shallow earthquakes. The source scaling an d attenuation models allow a satisfactory prediction of the peak ground acc eleration for magnitudes 5.1 less than or equal to M less than or equal to 6.5 and distances up to about 200 km in the Taiwan region, and may be usefu l for seismic hazard assessment. Copyright (C) 2000 John Wiley & Sons, Ltd.