Imbricated Aseismic Slip and Fluid Diffusion Drive a Seismic Swarm in the Corinth Gulf, Greece
Imbricated Aseismic Slip and Fluid Diffusion Drive a Seismic Swarm in the Corinth Gulf, Greece
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DOI：
10.1029/2020gl087142
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发表时间：
2020-05-16
影响因子：
5.2
通讯作者：
Dublanehet, Pierre
中科院分区：
文献类型：
--
作者：
De Barros, Louis;Cappa, Frederic;Dublanehet, Pierre
驱动地震群的主要过程仍在争论之中。在这里，我们研究了2015年10月发生在科林斯湾（希腊）伸展裂谷的10天内的地震群的时间演化。地震活动在正断层上以流体扩散速度（约125 m/d）径向迁移。然而，这种迁移是间歇性的，在短地震爆发期间的快速扩张期（2至10公里/天）与静止期交替出现。此外，群体的增长阶段照亮了大量的中继器。群体迁移可能是多种驱动过程相结合的结果。断层中的流体上升流可能会引起非稳态滑动，由流体压力上升阶段分隔。由于地震滑动的应力扰动可能会激活小的凹凸不平，在震群最强烈的阶段产生地震活动的爆发。
The primary processes driving seismic swarms are still under debate. Here, we study the temporal evolution of a seismic swarm that occurred over a 10-day period in October 2015 in the extensional rift of the Corinth Gulf (Greece) using high-resolution earthquakes relocations. The seismicity radially migrates on a normal fault at a fluid diffusion velocity (similar to 125 m/day). However, this migration occurs intermittently, with periods of fast expansion (2 to 10 km/day) during short seismic bursts alternating with quiescent periods. Moreover, the growing phases of the swarm illuminate a high number of repeaters. The swarm migration is likely the results of a combination of multiple driving processes. Fluid upflow in the fault may induce aseismic slip episodes, separated by phases of fluid pressure build-up. The stress perturbation due to aseismic slip may activate small asperities that produce bursts of seismicity during the most intense phases of the swarm.