HR: 0800h
AN: S11A-0274    [Abstracts]
TI: Long-Period simulations of Osaka basin wave propagation due to subduction earthquakes
AU: Oprsal, I
EM: io@egmdpri01.dpri.kyoto-u.ac.jp
AF: Disaster Prevention Research Institute, DPRI, Kyoto University, Gokasho, Uji, Kyoto, 611- 0011,
AU: * Iwata, T
EM: Iwata@egmdpri01.dpri.kyoto-u.ac.jp
AF: Disaster Prevention Research Institute, DPRI, Kyoto University, Gokasho, Uji, Kyoto, 611- 0011,
AB: Long-period ground motion characteristics of the Osaka basin are important for strong ground motion prediction due to the large subduction earthquakes of the Nankai trough. Among the previous studies for the Osaka basin ground motion characteristics, Hatayama et al. (1995) pointed out distinctive later phases observed at the OSA station approximately 30s after the S-wave arrival due to the deep events. They interpreted this later arrival is the basin-induced Love waves generated by the basin edge of the Eastern direction by the 2D anti-plane modeling. We tried to model the Osaka-basin induced waves of predominant frequency 0.3 Hz by the 3d FD hybrid method using the 3D basin velocity structure by Kagawa et al.(2004). The two of the three earthquakes investigated in Hatayama et al. (1995) are studied. The later arrivals of S waves (namely SL1 phase) in 3D model at the OSA station are in a good agreement with observation. The time difference between SL1(observed) and SL1"(synthesized) is smaller in full 3D case synthetics, than in 2D case modeling (Hatayama et al., 1995) for EW profile. We investigate a possibility of the later SL1 phase arrival due to it's possible arrival from other than Eastern directions.
DE: 0545 Modeling (4255)
DE: 0560 Numerical solutions (4255)
DE: 3200 MATHEMATICAL GEOPHYSICS (0500, 4400, 7833)
DE: 3285 Wave propagation (0689, 2487, 4275, 4455, 6934)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: 2007 Fall Meeting