| DOI: | 10.1038/ngeo2419
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| 论文题名: | Low friction and fault weakening revealed by rising sensitivity of tremor to tidal stress |
| 作者: | Houston H.
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| 刊名: | Nature Geoscience
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| ISSN: | 17520894
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| 出版年: | 2015
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| 卷: | 8, 期:5 | | 起始页码: | 409
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| 结束页码: | 415
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| 语种: | 英语
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| Scopus关键词: | fault slip
; friction
; mathematical analysis
; plate tectonics
; seismic wave
; sensitivity analysis
; stress change
; strike-slip fault
; thrust
; tidal cycle
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| 英文摘要: | At subduction zones, the level of friction on the deep part of the plate boundary fault controls stress accumulation and release, which govern the transfer of stress to the shallower, locked part of the fault that can slip in a megathrust earthquake. In some subduction zones, the deep fault slips slowly, at speeds far less than shallower, regular earthquakes, and is often accompanied by weak seismic waves called tremor. Tremor and slow slip can be triggered by small stress changes induced by ocean or solid Earth tides. Here I use seismic data combined with calculations of tidal stress to determine the influence of tides on 31,000 tremors generated by six large slow-slip events in Cascadia between 2007 and 2012. I find that the sensitivity of tremor to tidal stresses rises during each slip event, as slip at each spot on the fault accumulates. Specifically, tremor rate is an exponential function of tidal stress, and this exponential sensitivity grows for several days, implying that the fault weakens during slip. I use the relationship between tidal stress and tremor to calculate a coefficient of intrinsic friction for the fault and find values of 0 to 0.1, which indicate that the deep fault is inherently weak. © 2015 Macmillan Publishers Limited. All rights reserved. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/106288
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| Appears in Collections: | 气候减缓与适应
科学计划与规划
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作者单位: | Department of Earth and Space Sciences, University of Washington, Johnson Hall 070, 4000 15th Avenue NE, Seattle, WA, United States
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| Recommended Citation: | |
Houston H.. Low friction and fault weakening revealed by rising sensitivity of tremor to tidal stress[J]. Nature Geoscience,2015-01-01,8(5)
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