2013 Fiscal Year Final Research Report
Effect of periodic loading on asperity rupture
| Project/Area Number |
23540492
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KATO Naoyuki 東京大学, 地震研究所, 教授 (60224523)
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| Co-Investigator(Kenkyū-buntansha) |
TSURUOKA Hiroshi 東京大学, 地震研究所, 准教授 (10280562)
IGARASHI Toshihiro 東京大学, 地震研究所, 助教 (10334286)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 地震活動 / アスペリティ / 潮汐 / 数値シミュレーション / 摩擦特性 |
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| Research Abstract |
We investigated the effects of tidal stress on occurrence of low-frequency earthquakes and small repeating earthquakes in Japan. While statistically significant phase selectivity was found for the low-frequency earthquakes, no significant result was obtained for the small repeating earthquakes. The characteristics of phase selectivity changed after the 2011 Tohoku-oki earthquake.
Assuming periodic stress perturbation and rate- and state-dependent friction on the fault, we conducted a numerical simulation of asperity rupture. When the amplitude of periodic stress is the same, phase selectivity of asperity rupture is more significant for smaller fracture energy at the asperity. This result indicates that the fracture energy of small repeating earthquakes may be estimated from the observation of phase selectivity.
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