Slip Distributions of Short‐Term Slow Slip Events in Shikoku, Southwest Japan, From 2001 to 2019 Based on Tilt Change Measurements
Slip Distributions of Short‐Term Slow Slip Events in Shikoku, Southwest Japan, From 2001 to 2019 Based on Tilt Change Measurements
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基于倾斜变化测量的2001年至2019年日本西南部四国短期慢滑移事件的滑移分布
DOI：
10.1029/2020jb019601
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Takeshi Kimura
中科院分区：
文献类型：
--
作者：
H. Hirose;Takeshi Kimura
在日本西南俯冲带，伴随着非火山性震颤（ETS：幕式震颤和滑动）的短期缓慢滑动事件（SSE）反复发生，复发间隔为数月。了解SSE的详细滑动区域非常重要，因为短期SSE发生在大型逆冲断层地震破裂带的下倾延伸处，因此，SSE在大型逆冲断层地震的应力积累过程中起着关键作用。虽然大多数以前的研究模型的SSE断层运动与均匀滑动的矩形故障，这可能会导致在估计滑动面积的偏差。在这项研究中，我们估计的空间滑动分布的每个短期SSE倾斜偏移测量。总共获得了2001年1月至2019年3月四国61个SSE的滑动分布。四国ETS带根据SSE的滑动历史分为三段。在2011年以前，大部分SSE的滑动区域仅限于三个区段中的任何一个区段。然而，在2012年之后，具有延伸到多个区段的滑动区域的SSE的数量增加。ETS区域每个位置的滑动历史表明，短期SSE活动受到附近长期SSE发生的影响。18年来的平均滑动率表明，四国西部ETS地区的滑动赤字可能会被长期的SSE或同震滑动或大逆冲地震的后遗滑动所释放。
In the southwest Japan subduction zone, short‐term slow slip events (SSEs) accompanying nonvolcanic tremor (ETS: episodic tremor and slip) occur repeatedly with recurrence intervals of several months. It is important to know the detailed slip areas of the SSEs because short‐term SSEs occur at the downdip extension of a megathrust earthquake rupture zone, and hence, the SSEs play a key role in the stress buildup processes of the megathrust earthquakes. Although most of the previous studies model a SSE fault motion with uniform slip on a rectangular fault, this may lead to a bias in estimating the slip area. In this study we estimate a spatial slip distribution for each of the short‐term SSEs from tilt offset measurements. In total, the slip distributions of 61 SSEs in Shikoku from January 2001 to March 2019 are obtained. The ETS zone in Shikoku is divided into three segments in terms of slip history of the SSEs. Before 2011, the slip areas of most of the SSEs are limited in any one of the three segments. After 2012, however, the number of SSEs having a slip area that extends to multiple segments increases. The slip histories at each position in the ETS zone suggest that the short‐term SSE activity is affected by the occurrence of nearby long‐term SSEs. The average slip rate over 18 years suggests that an estimated slip deficit in the ETS zone in western Shikoku could be released by long‐term SSEs, or coseismic slip or afterslip of the megathrust earthquakes.
影响因子：
3
作者：
Y. Okada
通讯作者：
Y. Okada
影响因子：
64.8
作者：
Ide, Satoshi;Beroza, Gregory C.;Uchide, Takahiko
通讯作者：
Uchide, Takahiko
影响因子：
56.9
作者：
Obara, K
通讯作者：
Obara, K