气候变化领域集成服务门户(CCPortal): Stress Orientations in the Nankai Trough Constrained Using Seismic and Aseismic Slip

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DOI	10.1029/2020JB019841
	Stress Orientations in the Nankai Trough Constrained Using Seismic and Aseismic Slip
	Newton T.J.; Thomas A.M.
发表日期	2020
ISSN	21699313
卷号	125 期号:7
英文摘要	The strength of subduction thrust faults is key to understanding seismogenesis at the provenance of Earth's largest earthquakes. Earthquake focal mechanisms are routinely inverted to constrain the stress state at seismogenic depths. However, on some megathrusts, deformation is accommodated by both earthquakes and types of slow fault slip. We employ focal mechanisms of short-term slow slip events (SSEs), a type of slow fault slip, and earthquakes in a regional stress inversion to investigate the stress state of the Nankai Trough megathrust and interpret the results in the context of regional tectonics Previous studies using earthquake-only stress inversions found principal stress orientations in this region that are incompatible with thrust faulting on the megathrust. When both SSEs and earthquakes are considered, the stress state of the central and eastern Nankai Trough megathrust is well oriented for thrust faulting. Our results suggest that slow fault slip source regions may appear to have misoriented stress fields if slow fault slip constitutes a substantial proportion of fault slip and the stress field is not well constrained by earthquakes. In the SSE region, we find that faults are well oriented for failure, suggesting they have strengths similar to their surroundings. Combined with low Vp/Vs ratios and sensitivity to small stress changes, our results imply that the megathrust and surroundings operate at low deviatoric stresses in the SSE source region. Further, we show that the coefficient of friction for areas hosting SSEs is low (μ=0.19–0.50), implying frictionally weak materials in the SSE source region. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	fault mechanics; focal mechanism; megathrust; slow slip; stress inversion; subduction
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187759
作者单位	Department of Earth Sciences, University of Oregon, Eugene, OR, United States
推荐引用方式 GB/T 7714	Newton T.J.,Thomas A.M.. Stress Orientations in the Nankai Trough Constrained Using Seismic and Aseismic Slip[J],2020,125(7).
APA	Newton T.J.,&Thomas A.M..(2020).Stress Orientations in the Nankai Trough Constrained Using Seismic and Aseismic Slip.Journal of Geophysical Research: Solid Earth,125(7).
MLA	Newton T.J.,et al."Stress Orientations in the Nankai Trough Constrained Using Seismic and Aseismic Slip".Journal of Geophysical Research: Solid Earth 125.7(2020).