3-dimensional seismic velocoty structure beneath the Japan Islands reveled by seismic velocity discontinuity tomogarphy

2015 Fiscal Year Final Research Report

• Project/Area Number: 24340103
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Kyoto University
• Principal Investigator: HIRAHARA KAZURO 京都大学, 理学(系)研究科(研究院), 教授 (40165197)
• Co-Investigator(Renkei-kenkyūsha): OHKURA Takahiro 京都大学, 大学院理学研究科, 教授 (40233077)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: トモグラフィー / 地震波不連続面 / モホ面 / スラブ / レシーバ関数 / 地震波干渉法 / 地震発生サイクルシミュレーション

Outline of Final Research Achievements

In addition to direct P and S wave arrivals, we add the travel times of the later phases, which are Ps converted phases obtained from Receiver Functions and the reflected phases recorded by seismic interferometry to estimate the 3-D seismic velocity structure including velocity discontinuity interfaces, which is called 'seismic velocity discontinuity tomography'. However, there remains a problem that is the less accuracy of estimated arrival times of both Ps converted and reflected phases. And the inversion code for simultaneously estimating both velocity discontinuity interfaces and 3-D velocities has not yet completely developed. We need further improvements in obtaining the arrival times of later phases and in developing the inversion code. Furthermore, we developed earthquake cycle simulation codes for considering the non-planar earth’s surface and plate interfaces which are estimated by velocity discontinuity analyses.

Free Research Field

固体地球物理学　地震学