气候变化领域集成服务门户(CCPortal): Stress Release Process Along an Intraplate Fault Analogous to the Plate Boundary: A Case Study of the 2017 M5.2 Akita-Daisen Earthquake, NE Japan

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DOI	10.1029/2020JB019527
	Stress Release Process Along an Intraplate Fault Analogous to the Plate Boundary: A Case Study of the 2017 M5.2 Akita-Daisen Earthquake, NE Japan
	Yoshida K.; Taira T.; Matsumoto Y.; Saito T.; Emoto K.; Matsuzawa T.
发表日期	2020
ISSN	21699313
卷号	125 期号:5
英文摘要	Stress accumulation and release inside the plate remains poorly understood compared to that at the plate boundaries. Spatiotemporal variations in foreshock and aftershock activities can provide key constraints on time-dependent stress and deformation processes inside the plate. The 2017 M5.2 Akita-Daisen intraplate earthquake in NE Japan was preceded by intense foreshock activity and triggered a strong sequence of aftershocks. We examine the spatiotemporal distributions of foreshocks and aftershocks and determine the coseismic slip distribution of the mainshock. Our results indicate that seismicity both before and after the mainshock was concentrated on a planar structure with N-S strike that dips steeply eastward. We observe a migration of foreshocks toward the mainshock rupture area, suggesting the possibility that foreshocks were triggered by aseismic phenomena preceding the mainshock rupture. The mainshock rupture propagated toward the north, showing less slip beneath foreshock regions. The stress drop of the mainshock was 1.4 MPa, and the radiation efficiency was 0.72. Aftershocks were intensely triggered near the edge of large coseismic slip regions where shear stress increased. The aftershock region expanded along the fault strike, which can be attributed to the postseismic aseismic slip of the mainshock. We find that the foreshocks, mainshock, aftershocks, and postseismic slip released stress at different segments along the fault, which may reflect differences in frictional properties. Obtained results were similar to those observed for interplate earthquakes, which supports the hypothesis that the deformation processes along plate boundaries and intraplate faults are fundamentally the same. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	aseismic slip; hypocenter migration; intraplate earthquake; pore pressure; stress release; waveform inversion
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/187869
作者单位	Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan; Berkeley Seismological Laboratory and Department of Earth and Planetary Science, University of California, Berkeley, CA, United States; National Research Institute for Earth Science and Disaster Resilience, Tsukuba, Japan
推荐引用方式 GB/T 7714	Yoshida K.,Taira T.,Matsumoto Y.,et al. Stress Release Process Along an Intraplate Fault Analogous to the Plate Boundary: A Case Study of the 2017 M5.2 Akita-Daisen Earthquake, NE Japan[J],2020,125(5).
APA	Yoshida K.,Taira T.,Matsumoto Y.,Saito T.,Emoto K.,&Matsuzawa T..(2020).Stress Release Process Along an Intraplate Fault Analogous to the Plate Boundary: A Case Study of the 2017 M5.2 Akita-Daisen Earthquake, NE Japan.Journal of Geophysical Research: Solid Earth,125(5).
MLA	Yoshida K.,et al."Stress Release Process Along an Intraplate Fault Analogous to the Plate Boundary: A Case Study of the 2017 M5.2 Akita-Daisen Earthquake, NE Japan".Journal of Geophysical Research: Solid Earth 125.5(2020).