2018 Fiscal Year Final Research Report
Study on the physical mechanism of slow slip events based on crustal deformation and earthquake activity
Project/Area Number |
16K05542
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Solid earth and planetary physics
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Research Institution | Kobe University |
Principal Investigator |
Hirose Hitoshi 神戸大学, 都市安全研究センター, 准教授 (00465965)
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Research Collaborator |
MATSUZAWA Takanori
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Project Period (FY) |
2016-04-01 – 2019-03-31
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Keywords | 地殻変動 / GNSS / 傾斜 / 断層すべり / 沈み込み帯 / 応力変化 / グーテンベルグ・リヒター則 / b値 |
Outline of Final Research Achievements |
We investigated the relationship between slow slip events (SSE) that occur every few years off the Boso Peninsula and accompanying earthquake swarm activity. Assuming that stress changes due to SSE promote the occurrence of earthquakes, we developed an inversion method of time-dependent slip with a constraint that stress changes in places where earthquakes occur are not negative. It is shown that a slip area could be well constrained. The nature of the earthquake activity as a group was investigated. It was found that the b value of earthquakes occurring during Boso SSE periods is smaller than that of other periods.
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Free Research Field |
地震学
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Academic Significance and Societal Importance of the Research Achievements |
GPSなどの地殻変動観測データの解析により、地下で発生する断層すべりを推定しようとする研究は多数行われてきたが、応力変化をその制約条件に使うという研究はほとんどなく、その学術的意義は大きい。またSSE時の群発地震の性質からも応力場についての情報が得られる可能性もある。 このような試みによって、すべり領域がより精度良く推定できれば、同じ断層のすべり現象である地震の規模のより良い推定につながる可能性があると考えられ、社会的な意義もある。
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