Spatiotemporal Variations of Intermediate‐Depth Earthquakes Before and After 2011 Tohoku Earthquake Revealed by a Template Matching Catalog
Spatiotemporal Variations of Intermediate‐Depth Earthquakes Before and After 2011 Tohoku Earthquake Revealed by a Template Matching Catalog
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DOI：
10.1029/2023gl104068
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发表时间：
2023-11
影响因子：
5.2
通讯作者：
Qiushi Zhai;Zhigang Peng;Makoto Matsubara;K. Obara;Yanbin Wang
中科院分区：
文献类型：
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作者：
Qiushi Zhai;Zhigang Peng;Makoto Matsubara;K. Obara;Yanbin Wang
我们研究了2011年东北9级地震前后日本中部和东北部双地震带中深度地震的时空变化。我们使用 Hi-net 录音在东北地震前一年和后一年建立了模板匹配目录。与日本气象厅目录相比，新目录中的地震增加了六倍。我们的结果显示，东北地震前中深度地震发生率没有显着变化，但东北地震后两个平面的地震发生率均明显增加。中深度地震活动增加的区域和东北地震后的震后滑移区域在空间上分离且相互补充。东北地震后，两个平面的中深度地震余震生产力均有所增加。总体而言，上平面的余震生产力高于下平面，这可能表明两个平面的中深度地震的应力环境和物理机制是不同的。
We investigate spatiotemporal changes of intermediate‐depth earthquakes in the double seismic zone beneath Central and Northeastern Japan before and after the 2011 magnitude 9 Tohoku earthquake. We build a template‐matching catalog 1 year before and 1 year after the Tohoku earthquake using Hi‐net recordings. The new catalog has a six‐fold increase in earthquakes compared to the Japan Meteorological Agency catalog. Our results show no significant change in the intermediate‐depth earthquake rate prior to the Tohoku earthquake, but a clear increase in both planes following the Tohoku earthquake. The regions with increased intermediate‐depth earthquake activity and the post‐seismic slips following the Tohoku earthquake are spatially separate and complementary with each other. Aftershock productivity of intermediate‐depth earthquakes increased in both planes following the Tohoku earthquake. Overall, aftershock productivity of the upper plane is higher than the lower plane, likely indicating that stress environments and physical mechanisms of intermediate‐depth earthquakes in the two planes are distinct.