2013 Fiscal Year Final Research Report
Seismological study about the physical process of intermediate-depth earthquakes
| Project/Area Number |
22540438
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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 |
Solid earth and planetary physics
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| Research Institution | Kyoto University |
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Principal Investigator |
KUGE Keiko 京都大学, 理学(系)研究科(研究院), 准教授 (50234414)
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| Project Period (FY) |
2010-10-20 – 2013-03-31
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| Keywords | 稍深発地震 / 海洋プレート / 温度 / 水 |
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| Research Abstract |
The number of intermediate-depth earthquakes has locally the minimum in the depth range of 75-100 km, irrespective of subduction zones. This implies that the seismic activity can depend on thermal structure affected by the location where the subducting oceanic plate and high-temperature wedge mantle meet. The location can be estimated by observing later arrivals of P and S waves from intermediate-depth earthquakes. Well resolved slip propagation of a large intermediate-depth earthquake shows that the apparent rupture propagation velocity can be slower than the S-wave speed. The existence of water released from dehydration reactions can accelerate earthquake dynamic rupture due to dynamic weakening. To slow down the rupture, some process should act efficiently at the rupture front, such as plastic change in porosity.
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