Pore pressure dependences on frictional behavior of rocks and implications for slow earthquakes
Project/Area Number |
15H06890
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Research Category |
Grant-in-Aid for Research Activity Start-up
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Allocation Type | Single-year Grants |
Research Field |
Geology
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Research Institution | Chiba University |
Principal Investigator |
SAWAI Michiyo 千葉大学, 大学院理学研究科, 特任助教 (20760995)
|
Research Collaborator |
TAKAHASHI Miki
|
Project Period (FY) |
2015-08-28 – 2017-03-31
|
Project Status |
Completed (Fiscal Year 2016)
|
Budget Amount *help |
¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
|
Keywords | 間隙水圧 / 有効応力 / スロー地震 / 藍閃石片岩 / 花崗岩 / 地震発生 / 摩擦挙動 / 摩擦 / 沈み込み帯 |
Outline of Final Research Achievements |
Frictional property of rocks composed of a subducting oceanic plate is one of factors for controlling the diverse slip behavior from aseismic to seismogenic slip at the Japan Trench. Although alteration of fluid pressure in a fault zone during interseismic periods could occur in nature, the effects of fluid pressure on the fault parameters are not investigated systematically so far. Thus, we have conducted friction experiments on blueschist from Franciscan Belt, California and Westerly granite under high temperature and high pressure conditions and paid attention to how fault-stability parameters change with fluid pressure. Blueschist rocks show a transition from stable to unstable behavior with decreasing effective normal stress, which is mechanically equivalent to increasing fluid pressure, whereas granite rocks show the opposite trend and stable at high pore pressure conditions. Our results might suggest that fault instability for the pore pressure depend on its materials.
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Report
(3 results)
Research Products
(10 results)