This study presents the relation between the an estimatedion of P-wave attenuation characteristics accross the active fault line and the stress state characteristics of the fault their relation to the active faults forcovering the 12 major active faults zones in Japan. We employed a twofold spectral ratio method to estimate the attenuation characteristics of the active faults. As a result of a review of the differences in the attenuation characteristics, a clear positive correlation with the ratio of the lapse time from the previous earthquake was confirmed. These results suggest that the attenuation characteristics estimated in this study may reflect the stress state of thean active fault.
The effects of two different ways of counting fault areas, that are the seismic fault area and the entire ruptured fault area, on the strong ground motions from the faults 30 km and 50 km long were small for peak ground accelerations and comparatively large for peak ground velocities and response spectra in the longer period range. On the other hand, the effects on the strong ground motions from the fault 200 km long were little for peak ground accelerations or peak ground velocities while the effects were a little for response spectra in the period range longer than 3 seconds.