中科大地球与行星物理学术报告通知-王巍

报告地点:教学行政楼706

报告时间:2022-09-23 从 15:00 到 16:30

报告人:王巍(南加州大学)

报告人简介:

王巍,美国南加州大学博士后。2010,2013年于中国科技大学获得本科和硕士学位, 2019年于加州大学圣地亚哥分校获得博士学位。2019年9月开始在南加州大学从事博士后研究。主要研究方向包括地球内部小尺度和非弹性性质反演,多尺度地震触发现象的观测及机制解释,小地震震源物理分析。目前在国际SCI期刊发表论文14篇,其中第一作者8篇。

报告题目:Tidal modulation of seismicity at the Coso geothermal field

报告内容简介

Studying the seismicity triggering response of fault systems to periodic stress fluctuations can improve our understanding of earthquake nucleation, rupture failure processes, and local stress states. Geothermal fields are well known to be susceptible to triggering, as the injection and extraction activities change the local stress and fluid flow conditions. Here, we examine the modulation of earthquakes by Earth tides within California's Coso geothermal field (CGF) and its vicinity. To maximize our resolution to detect modulation of small earthquakes, we take advantage of the new Quake Template Matching catalog in southern California, which has nearly twice as many events in the Coso region as the standard catalog and is complete down to about magnitude 0.3. We observe strong tidal triggering of earthquakes within the CGF, even though the fluctuations of tidal stresses are small (∼2 kPa). The tidally-triggered earthquakes tend to occur near the time of maximum tensile tidal stress. The signal is strongest near the edges of the zone of new production wells, suggesting fluid pressure gradients encourages triggering at tidal periods.