寻乌M_(L) 3.8震群遗漏地震检测与发震构造分析  

Missing earthquakes detection and seismogenic structure analysis of the Xunwu M_(L) 3.8 earthquake swarm

作　　者：汤兰荣 叶媛媛 曾新福 查小惠 陈江贻 曾先进 罗丽 TANG Lanrong;YE Yuanyuan;ZENG Xinfu;ZHA Xiaohui;CHEN Jiangyi;ZENG Xianjin;LUO Li(Jiangxi Earthquake Agency,Nanchang 330096,China;Gansu Earthquake Agency,Lanzhou 730000,China)

机构地区：[1]江西省地震局,南昌330096 [2]甘肃省地震局,兰州730000

出　　处：《地震地磁观测与研究》2024年第4期10-17,共8页Seismological and Geomagnetic Observation and Research

基　　金：江西省地震局科技创新团队项目;中国地震局监测、预报、科研三结合课题(项目编号:3JH-202401049)。

摘　　要：利用模板匹配滤波技术对2017年11月至2018年4月寻乌M_(L)3.8震群的遗漏地震事件进行检测,再利用波形互相关震相检测技术标定P、S波到时,采用双差定位方法进行重定位,结合震群分布、震源机制解、地质构造分析震群的发震构造。结果显示,对于寻乌M_(L)3.8震群共检测到遗漏地震36个,约为中国地震台网中心地震目录的47%,M_(L)<1.2地震的完整性有较明显改善。重定位后震群分布更加集中,沿NE向优势展布。垂直于震群优势展布方向的深度剖面显示,震源深度总体上由NW至SE逐渐变浅,推测可能的发震断层倾向NW。综合地质构造、精定位、震源机制解推测,此次震群的发震构造为吉潭—留车断裂。Matched filtering technology was used to detect missing seismic events in the Xunwu M_(L) 3.8 earthquake swarm from November 2017 to April 2018.Then we determined P and S wave arrival times using seismic phase detection technology based on waveform cross correlation method,and used double-difference relocation method for relocation,The seismogenic structure of the swarm was analyzed by combining the distribution of the swarm,source mechanism solutions,and geological structures.The results show that a total of 36 missing earthquakes were detected in the Xunwu earthquake swarm,which is about 47%of the catalogue of network,the catalog completeness is obviously improved for earthquakes below M_(L) 1.2.After relocation,the distribution of earthquake swarm becomes more concentrated,spreads along the NE direction.The depth profile perpendicular to the dominant distribution of the earthquake swarm shows that the depth of the earthquake source gradually shallows from NW to SE,suggesting a possible seismic fault inclination towards NW.Based on the geological structures,relocated earthquakes and focal mechanisms,it is speculated that the seismogenic structure of this earthquake swarm is the Jitan-Liuche fault.

关 键 词：寻乌M_(L)3.8震群 遗漏地震检测 模板匹配 震源机制解 双差定位 

分 类 号：P315[天文地球—地震学]