2018 Fiscal Year Final Research Report
Physicochemical mechanisms underlying frictional responses at slow to fast earthquakes: inferred from hydrothermal friction experiments
| Project/Area Number |
16H04064
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Geology
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| Research Institution | Japan Agency for Marine-Earth Science and Technology |
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Principal Investigator |
HIROSE Takehiro 国立研究開発法人海洋研究開発機構, 高知コア研究所, グループリーダー (40470124)
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| Research Collaborator |
TANIKAWA Wataru
TAKAHASHI Miki
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | スロー地震 / 断層 / 摩擦 / 熱水 |
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| Outline of Final Research Achievements |
Earthquakes involve a wide range of slip rates, from slow/aseismic to fast/seismic slip along faults. Frictional properties of faults over wide slip rates (nm/s to m/s), in particular under hydrothermal conditions similar to those expected in seismogenic zones, are thus essential for a unified understanding of all earthquake events. In this project, we have successfully developed a new hydrothermal, low to high speed rotary-shearing apparatus that is aimed to study in-situ frictional property of faults along subduction zones. Based on the experimental results on materials that potentially exist along the Tohoku plate boundary, we proposed frictional properties of the Tohoku plate boundary. Incorporating the properties in modeling of earthquakes generation, we expect to gain better understanding of diverse earthquakes along subduction zones.
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| Free Research Field |
岩石力学・構造地質
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| Academic Significance and Societal Importance of the Research Achievements |
地震震源域に実際に存在しうる岩石の高温熱水条件での摩擦特性を調べることは、ゆっくりとした地震から高速すべりをする巨大地震の発生機構とその関連性を調べる上で重要である。本研究によって、熱水環境下において多様な地震すべり速度条件で摩擦実験が可能な回転式熱水試験機をはじめて開発することができた。さらに実験結果から、東北プレート境界における断層すべり安定性モデルを構築することができた。今後、このようなモデルを用いた数値計算などにより、沈み込み帯で発生する多様な地震の発生に関する理解がより深まると期待される。
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