A PROPAGATION MECHANISM OF SURFACE WAVESINDUCED BY A SEDIMENTARY BASIN-A CASE STUDY IN THE OSAKA BASIN, JAPAN, DURING THE 1995HYOGO-KEN NANBU EARTHQUAKE-

摘要

For the prediction of long period ground motions in Osaka basin, we investigated the propagation andgeneration process of them in Osaka basin using the 1995 Hyogo-ken nanbu earthquake. The seismogramobserved at costal area (RKI) can be identified the long period later phase after 100sec of S-wave onset.From particle orbits and comparison of seismograms observed at other stations, there are some possibilitythat the propagation and generation process of the long period later phase is as following; (1): it was Lovewave generated at the seismic source, and propagated to RKI via Mt. Izumi where is located at oppositeside of RKI in Osaka basin. (2): it was Love wave generated at the bottom of mountain near RKI andpropagated to opposite side, it was reflected at Mt. Izumi, and returned to RKI. (3): it was Love wavegenerated at the bottom of Mt. Izumi, and propagated to RKI.