2020年古冶M_(S)5.1地震前后岩石圈磁场变化特征  

Analysis of the variation of the lithospheric magnetic field before and after the Guye M_(S)5.1 earthquake

作　　者：张娜 龚燕民 苏树朋 ZHANG Na;GONG Yanmin;SU Shupeng(Baoding Center Seismic Station,Hebei Province 071051,China)

机构地区：[1]保定地震监测中心站,中国河北071051

出　　处：《地震地磁观测与研究》2024年第2期60-67,共8页Seismological and Geomagnetic Observation and Research

基　　金：河北省地震科技星火计划攻关项目(项目编号:DZ2023120500001)。

摘　　要：总结归纳河北及邻近地区2014年以来4级以上中强地震震兆异常特征位置,结合2020年古冶M_(S)5.1地震发生前后岩石圈磁场H矢量、D、F总场3个要素地磁异常变化图像,分析发震前后岩石圈磁场震兆异常变化特征。结果表明:①河北及邻近地区7个M≥4地震均发生在岩石圈磁场各地磁要素0值线附近的高梯级带、0值线附近及矢量方向转向等特征部位;②古冶M_(S)5.1地震符合河北中强地震岩石圈磁场震兆异常空间位置特征,概率达75%;③丰南M_(S)4.5地震后唐山岩石圈磁场异常区异常特征出现增强,原地震危险区有再次发震的可能。In this paper,the authors summarize the characteristic locations of precursory anomalies of moderate and strong earthquakes with M≥4 in Hebei and its adjacent areas since 2014;combined with the image of H-vector,d-factor,f-total field and 3-factor geomagnetic anomaly changes in the lithosphere magnetic field of the Guye M_(S)5.1 and Fengnan District M_(S)4.5 earthquakes,the characteristics of precursor anomalies of the lithospheric magnetic field of Guye earthquake and Fengnan District earthquake are obtained.The results show that:①The 7 M≥4 earthquakes in Hebei and its adjacent areas all occurred in the high-step belt near the“0-value line”of each geomagnetic element of the lithospheric magnetic field,“Near 0-value line”,and the characteristic locations of the vector direction of the geomagnetic anomaly;②The Guye M_(S)5.1 earthquake accords with the characteristics of the spatial location of the precursory anomaly of the lithospheric magnetic field of the medium-strong earthquake in Hebei,with a probability of 75%;③After the Fengnan M_(S)4.5 earthquake,the anomaly characteristics of the Tangshan lithospheric magnetic field anomaly area were enhanced,and the risk area in situ had the possibility of another earthquake.

关 键 词：岩石圈磁场 流动地磁 2019年丰南M_(S)4.5地震 2020年古冶M_(S)5.1地震 

分 类 号：P31[天文地球—固体地球物理学]