2002 Volume 54 Issue 4 Pages 475-488
The three-dimensional attenuation structure of the Japanese islands and site amplification factors are obtained by simultaneous inversion of strong motion records recorded by many acceleration seismometers, i. e. JMA87-type seismometers and the Kyoshin-Net (K-NET) seismometers, almost uniformly distributed in Japan.
The result shows that the Pacific slab is high-Q and that the frequency dependence of Q values is expressed as f0.75.
We classified all stations into 5 groups by ground conditions mainly on the basis of S-wave logging data and obtained the site amplification factor for each group. The result shows that the frequency band where large amplification factors are obtained by inversion well agrees with the predominant frequency calculated from S-wave velocity data.
