Stress change before and after the 2011 M9 Tohoku-oki earthquake
Stress change before and after the 2011 M9 Tohoku-oki earthquake
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DOI：
10.1016/j.epsl.2018.09.035
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发表时间：
2018-12-15
影响因子：
5.3
通讯作者：
Sato, Hiroshi
中科院分区：
文献类型：
--
作者：
Becker, Thorsten W.;Hashima, Akinori;Sato, Hiroshi
巨型逆冲断层系统为我们理解长期和短期板块边界动力学提供了重要线索，2011年东北冲地震提供了一个数据丰富的案例。在这里，我们表明，F-净矩张量目录表明，在导致M9的几年中，由于同震效应，地壳应力的系统性变化，并在过去几年中，由于粘性松弛。我们探索了成像的应力变化与M9粘弹松弛和后滑效应的3D力学模型预期的扰动之间的匹配。虽然这些模型是建立在大地测量和结构地震学的限制单独，他们匹配的地震推断的应力变化的许多特点。这为我们理解日本海沟的板块边界动力学提供了新的线索。探索地壳应力变化的确定性方法的成功也意味着利用震源机制和大地测量约束的应力进行联合反演是可行的。今后的这种努力应能对与时间有关的地震危险，包括地震触发情景，提供重要的见解。(C)2018爱思唯尔B. V.保留所有权利。
Megathrust systems hold important clues for our understanding of long- and short-term plate boundary dynamics, and the 2011 M9 Tohoku-oki earthquake provides a data-rich case in point. Here, we show that the F-net moment tensor catalog indicates systematic changes in crustal stress in the years leading up to the M9, due to the co-seismic effect, and for the last few years due to viscous relaxation. We explore the match between imaged stress change and the perturbations that are expected from 3-D, mechanical models of the visco-elastic relaxation and afterslip effects of the M9. While these models were constructed based on geodetic and structural seismology constraints alone, they match many characteristics of the seismicity-inferred stress change. This provides additional confidence in the modeling approach, and new clues for our understanding of plate boundary dynamics for the Japan trench. The success of deterministic approaches for exploring crustal stress change also implies that joint inversions using stress from focal mechanisms and geodetic constraints may be feasible. Such future efforts should provide key insights into time-dependent seismic hazard including earthquake triggering scenarios. (C) 2018 Elsevier B.V. All rights reserved.