基于CAP方法的2019年湖北应城M_(S)4.9地震震源机制与发震构造研究  

Focal Mechanism Solution and Seismogenic Structure of the Ms4.9 Yingcheng Earthquake in 2019 from the CAP Method

作　　者：赵凌云[1,2,3] 丁文秀 周舟[1,2,3] 周本伟 何凯 申学林 魏贵春[1,2,3] ZHAO Lingyun;DING Wenxiu;ZHOU Zhou;ZHOU Benwei;HE Kai;SHEN Xuelin;WEI Guichun(Key Iabonatary of Farthquake Godey,Institule of Seismology,CEA,Hubei Wuhan 430071,China;Hubei Farthquake Agency,Hubei Wuhan 430071,China;Key Seismie Monitoring Sation of the Three Gorges Projext Eedlogical and En virnme ntal Monitoring System,Hubei Wuhan 430071,China)

机构地区：[1]中国地震局地震研究所(地震大地测量重点实验室),湖北武汉430071 [2]湖北省地震局,湖北武汉430071 [3]三峡工程生态与环境监测系统地震监测重点站,湖北武汉430071

出　　处：《四川地震》2022年第3期20-23,27,共5页Earthquake Research in Sichuan

基　　金：中国长江三峡集团有限公司专项(0799216);中国地震局测震三结合项目(3JH-202201038)联合资助

摘　　要：利用湖北区域台网8个台站的宽频带数字地震记录,采用CAP法反演了湖北应城2019年12月26日M_(S)4.9(M_(L)5.3)地震震源机制解。其最佳双力偶解:节面I走向49°,倾角78°,滑动角162°;节面Ⅱ走向143°,倾角72°,滑动角13°;主压应力P轴近EW向;主张应力轴近NS向;最佳震源深度约8.0km。其最大余震为2020年1月8日M_(S)2.6(M_(L)3.3)地震,余震序列呈NW分布。分析结果认为:此次地震由带有逆冲成分的走滑型断层错动造成,节面Ⅱ为发震断层且与皂市断裂有关。Based on the broadband digital seismic records from 9 stations in Hubei and Henan province,we used the CAP method to invert the focal mechanism of the M4.9 earthquake on December 26,2019 in Yingcheng,Hubei province.The optimal double coupling solution presents that the first nodal plane shows the strike at 49°,dip at78°,and rake at 162°,whereas the second nodal plane shows the strike at 143°,dip at 720 and rake at 12.6°.The optimal hypocenter depth is concentrated at approximately 8.0 km.The results show that the earthquake occurred on a strike-slip fault with thrust component.The axis of major compressive stress is nearly EW direction,whereas the axis of major tensile stress is nearly NS direction.The largest aftershock was the M_(s)2.6 earthquake near the epicenter on January 8,2020.The main aftershock sequence is distributed in NW direction.We suggest that the seismogenic fault is related to the Zaoshi fault.

关 键 词：应城M_(S)4.9地震 震源机制解 CAP法(Cutand Paste Method) 地震构造 

分 类 号：P315[天文地球—地震学]