Project/Area Number |
15K05259
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Solid earth and planetary physics
|
Research Institution | Tohoku University |
Principal Investigator |
Yabe Yasuo 東北大学, 理学研究科, 准教授 (30292197)
|
Project Period (FY) |
2015-04-01 – 2018-03-31
|
Project Status |
Completed (Fiscal Year 2017)
|
Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2015: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
|
Keywords | AE活動 / 断層摩擦 / 速度依存性 / 累積すべり量依存性 / 法線応力依存性 / 摩擦強度 / すべり速度依存性 / 断層面の摩耗 / AE活動 / AE波形連続収録 / 雰囲気制御 / 震源決定 |
Outline of Final Research Achievements |
Normal stress dependencies of evolution of the rate effect on frictional strength and AE activity were examined by laboratory experiments using granite specimens. For cumulative sliding distance smaller than a critical distance, the rate dependency of friction is positive, while that of the b-value of AE activity is negative. When the cumulative sliding distance reaches the critical distance, the rate dependence of friction turns to negative. At the same time, the rate dependence of the b-value of AE activity becomes negative. Higher the normal stress, the critical distance becomes smaller. The evolutions of rate effects on the friction and the AE activity can be approximated by an exponential function to estimate a characteristic sliding distance required to reach a steady state. The characteristic sliding distance is inversely proportional to the normal stress, suggesting a work done by external force to evolve fault surface topographies by wear is independent of the normal stress.
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