Stress state in the vicinity of the plate boundary fault ruptures during the 2011 Tohoku earthquake

2016 Fiscal Year Final Research Report

• Project/Area Number: 25287134
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Kyoto University (2016); Japan Agency for Marine-Earth Science and Technology (2013-2015)
• Principal Investigator: Lin Weiren (リンウェイレン) 京都大学, 工学(系)研究科(研究院), 教授 (80371714)
• Co-Investigator(Kenkyū-buntansha): 山本 裕二 高知大学, 教育研究部自然科学系理学部門, 准教授 (00452699)
• Co-Investigator(Renkei-kenkyūsha): TANIKAWA Wataru 国立研究開発法人海洋研究開発機構, 高知コア研究所, 主任研究員 (70435840) ; KINOSHITA Masataka 東京大学, 地震研究所, 教授 (50225009)
• Research Collaborator: TAKAHASHI Manabu 国立研究開発法人産業技術総合研究所, 地圏資源環境研究部門, 主任研究員 (20357370)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 応力 / 断層掘削 / 非弾性ひずみ回復 / ブレークアウト / 熱物性

Outline of Final Research Achievements

To investigate the relationship between behavior of seismic fault slipping and stress state in the vicinity of the fault and in the wall rocks, we conducted stress measurements in the ocean scientific drilling project JFAST penetrated into the plate boundary fault which ruptured during the 2011 Tohoku earthquake, and also developed the relative stress measurement techniques. As their results, we obtained the stress profile in the JFAST borehole, and the results enabled us to compare with the stress state spatial distribution in the Nankai Trough subduction zone where is the source region of the Tonankai and Nankai earthquakes. In addition, we determined the three heat transfer properties using the JFAST core samples, and contributed the interpretation on the temperature anomaly detected at depth around the plate boundary in the JFAST borehole.

Free Research Field

岩石力学、構造地質、地質工学