Aftershocks and Omori law in creep experiment on rocks
| Project/Area Number |
15H03698
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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 |
Mathematical physics/Fundamental condensed matter physics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Research Collaborator |
ROY Subhadeep 東京大学, 地震研究所, 特任研究員
TANAKA Hiroki 東京大学, 地震研究所, 大学院生
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Project Status |
Completed (Fiscal Year 2017)
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| Budget Amount *help |
¥13,520,000 (Direct Cost: ¥10,400,000、Indirect Cost: ¥3,120,000)
Fiscal Year 2017: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2016: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2015: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
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| Keywords | 余震 / 大森則 / 逆大森則 / ファイバーバンドルモデル / 地震 / クリープ / 破壊 / 平均場近似 / 自己組織化 / 前震 |
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| Outline of Final Research Achievements |
Two power laws are ubiquitously observed for the statistics of materials failure and earthquakes: the Gutenberg-Richter (GR) law and the Omori law. Interestingly, some parameters in these power laws may reflect the physical state of specimens or earthquake faults such as the stress level. Here we investigated the b-value in the GR law and the c-value in the Omori law focusing on their stress dependence in two distinct systems: granular matter and the bundle of fibers. In sheared granular matter, both the b-value and the c-value exhibit negative stress dependences. Particularly, we found the exponential dependence of the c-value on stress. In the fiber bundle model, we confirmed the Omori law and the inverse Omori law. An analytical solution is obtained for a mean-field model, which reveals slow down due to the saddle-node bifurcation. The c-value here depends on the degree of heterogeneity in the system rather than the stress.
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Report
(4 results)
Research Products
(15 results)
