Project/Area Number |
14540394
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
固体地球物理学
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Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
Principal Investigator |
OKAMOTO Taro Tokyo Institute of Technology, Earth and planetary Sciences, Research Associate, 大学院・理工学研究科, 助手 (40270920)
|
Co-Investigator(Kenkyū-buntansha) |
KANESHIMA Satoshi Tokyo Institute of Technology, Earth and Planetary Sciences, Associate Professor, 大学院・理工学研究科, 助教授 (80202018)
FUKAYAMA Eiichi Tokyo Institute of Technology, Earth and Planetary Sciences, Associate Professor, 固体地球科学研究部門, 主任研究員 (60360369)
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Project Period (FY) |
2002 – 2003
|
Project Status |
Completed (Fiscal Year 2003)
|
Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Keywords | surface wave / tomography / structure of Earth's interior |
Research Abstract |
We developed a membrane surface wave synthetic method. Its main features are (1) the effect of the 3D heterogeneity on the waveform may be evaluated by solving 2D potential function under the ansatz of the separation of the displacement into term of vertical variation (local eigenfunction) and term of horizontal variation (horizontal potential function), (2) numerical (direct) evaluation of the 2D potential functions for heterogeneous surface wave phase velocity distribution without asymptotic approximations, and (3) capability in evaluating the 3D tomographic kernels (partial derivatives). We made a preliminary, laterally heterogeneous model for the structure in and around Japanese Islands. The computed potentials and tomographic kernels indicate significant distortions (curved path and asymmetric pattern), especially at short periods around 10s for the model structure. The membrane surface wave synthetic for Rayleigh waves from an example event (2002 Off Boso Peninsula) earthquake assuming the laterally heterogeneous model shows more intense dispersion effect than the synthetic for a flat layered model does. We find that this dispersive feature resembles the characteristics in the observed wave forms, although the current structural model is still not sufficient in fully predicting the observation. We suggest the importance of the sedimentary layer especially for Love waves.
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