| Project/Area Number |
14540392
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体地球物理学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
YOSHIDA Shingo The University of Tokyo, Earthquake Research Institute, Associate Professor, 地震研究所, 助教授 (20202400)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Aitaro IFREE/JAMSTEC, Research Staff, Research Staff, JAMSTEC, 研究員 (20359201)
NAKATANI Masao The University of Tokyo, Earthquake Research Institute, Research Associate, 地震研究所, 助手 (90345174)
KATO Naoyuki The University of Tokyo, Earthquake Research Institute, Associate Professor, 地震研究所, 助教授 (60224523)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | asperity / aseismic slip / episodic slow slip / interaction / rate-and state-dependent friction law |
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| Research Abstract |
We studied various slip modes on a plate boundary on the basis of a two-degree-of-freedom block-spring model and large-scale biaxial experiments. Slip experiments were conducted using large granite blocks with a pre-existing fault surface of 100 cm in length. Velocity-strengthening friction was given over a half of the fault length by inserting a thin Teflon sheet, while the other half retained velocity-weakening friction of the bare rock surface. Under a loading at a constant velocity, dynamic stick-slip repeated on the velocity-weakening region, causing afterslip on the velocity-strengthening region. The velocity-strengthening region experienced small coseisic slip as well, with the magnitude decreasing with the distance from the velocity-weakening region. The behaviors observed in the laboratory experiments were quantitatively simulated by a two-degree-of-freedom block-spring model, in which two blocks (Block 1 and Block 2) are connected by a liner spring and driven by a slowly moving driver. The friction on each block was assumed to obey rate and state dependent friction law. When a-b was assumed to be negative for Block 1, and positive for Block 2, afterslip occurred at Block 2. This model can also reproduce wide spectrum of slip modes observed on a plate-boundary, including episodic slow slip.
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