Frequency dependent attenuation function and fourier amplitude spectra of strong earthquake ground motion in California, 1995

This report presents the third generation of empirical equations for direct scaling at Fourier amplitude spectra of strong ground motion in California. Simultaneously we present a new, path and frequency dependent, attenuation function for spectral amplitudes versus distance between the causative fault and the recording station.; The results show major improvements in the empirical scaling equations relative to the former models from 1976 (first generation) and 1985 (second generation). These improvements were feasible because a) the number of strong motion recordings which could be used in the analysis grew to about 2000 (compared to 186 in mid 1970's and 55 in mid 1980's), and because b) of the detailed and systematic characterization of the recording sites by local geological and local soil site parameters.