2020年北京顺义震群发震机理  

Mechanism Analysis of the 2020 Beijing Shunyi Earthquake Swarm

作　　者：宋程 马婷[1] 徐小远[1] 谭毅培[1] SONG Cheng;MA Ting;XU Xiaoyuan;TAN Yipei(Tianjin Earthquake Agency,Key Laboratory of Earthquake Engineering Simulation and Seismic Resilience of China Earthquake Administration,Tianjin 300201,China)

机构地区：[1]天津市地震局中国地震局地震工程综合模拟与城乡韧性抗震重点实验室,天津300201

出　　处：《华北地震科学》2022年第1期71-76,共6页North China Earthquake Sciences

基　　金：2021年度震情跟踪定向任务(2021010128);天津市地震局局内科研项目(yb202001);地震科技星火计划项目(XH21002Y)。

摘　　要：以2020年3—4月北京顺义小震群为研究对象,进行模板匹配遗漏地震检测、波形互相关震相检测、地震精定位、震源机制计算、破裂半径和应力降等震源参数计算,以探究其发震机理。计算结果显示:①顺义震群发震构造为NW走向,震中呈现由NW向SE的迁移特征;②除了震群中第一个M_(L)2.4地震无法计算外,另外2次M_(L)2.0以上地震的破裂面均处于之前地震产生的静态应力加载区内;③未检测到震群中存在重复地震活动。结合前人提出的震群发震机理模型,分析认为随机性模型可以较好地解释以上计算结果,顺义震群的发震机理可以解释为地震间的应力触发作用,此研究结果可为北京地区地震危险性分析提供科学参考。In order to explore the seismogenesis mechanism of the Beijing Shunyi earthquake swarm in March and April 2020,the missing earthquake detection of template matching,waveform cross-correlation phase detection,earthquake precise location,focal mechanism calculation,rupture radius and stress drop and other focal parameters were carried out.The results show that:①The seismogenic structure of the Shunyi swarm is NW trending,and the epicenter show the migration characteristics from NW to SE.②Except for the first M_(L)2.4 earthquake in the swarm that cannot be calculated,the rupture area of the other largest two M_(L)≥2.0 earthquakes are in the static stress loading area generated by previous earthquakes.③No repeating earthquakes were detected in the swarm.Combined with the mechanism model of earthquake swarm proposed by predecessors,it is analyzed that the random model can well interpreted the above results.The results of this article may provide scientific reference for seismic risk analysis in Beijing area.

关 键 词：顺义震群 地震精定位 静态应力触发 发震机理 

分 类 号：P315.6[天文地球—地震学]