山西北部地区中小地震重定位结果分析  

Analysis of Relocation Results of Small and Medium Earthquakes in Northern Shanxi Province

作　　者：刘林飞[1,2] 梁向军[1,2] 黄金刚[1,2] 宋美琴[1,2] LIU Linfei;LIANG Xiangjun;HUANG Jingang;SONG Meiqin(Shanxi Earthquake Agency,Shanxi Taiyuan 030021,China;National Continental Rift Valley Dynamics Observatory of Taiyuan, Shanxi Taiyuan 030021,China)

机构地区：[1]山西省地震局,山西太原030021 [2]太原大陆裂谷动力学国家野外科学观测研究站,山西太原030021

出　　处：《四川地震》2020年第4期23-27,共5页Earthquake Research in Sichuan

基　　金：山西省地震局科研项目(SBK-2021);中国地震局星火计划项目(XH20010);预测所科研专项(2017IES010104和2017IES010105);山西省科技厅项目(201801D221044);2019年度震情跟踪专项工作任务(2019010106)资助.

摘　　要：利用山西省测震台网2010~2019年的观测报告数据,采用双差定位方法对山西北部地区ML≥1.0地震重新进行了精确定位。结果显示:震源位置定位误差EW向为0.491 km,NS向为0.469 km,UD向为0.807 km,定位后的均方根残差为0.242 s;重新定位后的地震震中平面分布与定位前的相比较,定位后的震中空间分布更加集中,沿断裂带展布,主要分布在大同盆地和忻定盆地,在两侧隆起区地震分布较少;重新定位后的深度比定位前更加合理,优势深度分布在6~25 km,基本发生在中、上地壳;7级历史强震破裂区内现今小震活动的频度较低、水平较弱,山西大同盆地中、小地震的活动性相对较高,应该引起重视。Based on the observation data of Shanxi seismograph network from 2010~2019,the relocation of ML≥1.0 earthquake in the northern Shanxi Province was reperformed by using the double-difference location method.The results show that the EW error of epicenter location is 0.491 km,NS is 0.469 km,UD is 0.807 km,and the root-mean-square residual after relocation is 0.242 s.The spatial distribution of the earthquake epicenter after the relocation is more concentrated and distributed along fault zones,mainly in Datong basin and Xinding Basin,and less in uplift areas on both sides.The depth after relocation is more reasonable than before relocation,and the dominant depth is distributed in 6~25 km,which basically occurs in the middle and upper crust.The frequency and magnitude of small earthquakes in the rupture zone of magnitude 7 historical strong earthquakes are relatively low,and the activity of medium and small earthquakes in datong Basin of Shanxi is relatively high,which should be paid attention to.

关 键 词：中小地震 山西北部 重新定位 

分 类 号：P315.5[天文地球—地震学]