2021年5月22日青海玛多7.4级地震前地磁日变化异常分析  

Analysis on Geomagnetic Diurnal Variation Anomaly Before the M_(S)7.4 Maduo Earthquake

作　　者：李军辉[1,2] 姜楚峰 冯丽丽 何康[1] LI Junhui;JIANG Chufeng;FENG Lili;HE Kang(Anhui Earthquake Agency,Anhui Hefei 230031;National Geophysical Obvervatory at Mengcheng,Anhui Mengcheng 233527;Hubei Earthquake Agency,Hubei Wuhan 430071;Qinghai Earthquake Agency,Qinghai Xining 810001)

机构地区：[1]安徽省地震局,安徽合肥230031 [2]安徽蒙城地球物理国家野外科学观测研究站,安徽蒙城230031 [3]湖北省地震局,湖北武汉430071 [4]青海省地震局,青海西宁810001

出　　处：《四川地震》2021年第4期7-11,共5页Earthquake Research in Sichuan

基　　金：中国地震局地震科技星火计划项目(XH200501).

摘　　要：2021年5月22日青海玛多发生7.4级地震,全国地磁学科组在该地震发生前提出了地磁日变化空间相关重叠异常。本研究计算了青海玛多7.4级地震前2019~2020年150个台站地磁垂直分量日变化相关系数,结果显示:2020年9月26日和9月28日在震中附近分别出现6个和12个台站的地磁Z分量日变化明显反相位异常,该异常具有明显的分界线;2020年9月26日和2020年9月28日的相关系数0值线出现重叠异常,该异常从青海至四川中部呈现反S形态,在该异常出现8个月后,在重叠异常青海段的端部200 km范围发生了玛多7.4级地震。The M_(S)7.4 Maduo earthquake occurred in Qinghai Province on May 22,2021.The spatial correlation anomalies of geomagnetic daily variation are proposed before the earthquake.In this paper,the daily variations of geomagnetic vertical component of 150 stations from 2019 to 2020 before the M_(S)7.4 Maduo earthquake are further calculated and analyzed.The results show that the diurnal variations of the geomagnetic Z component of 6 and 12 stations near the epicenter on September 26 and 28,2020,respectively,present obvious anti-phase anomalies that are characterized by a clear dividing line.The zero value lines of the correlation coefficient on September 26 and 28,2020 are abnormally overlapped.The overlapping anomalies present an anti-S form from Qinghai to central Sichuan.The M_(S)7.4 Maduo earthquake occurred within 200 km at the end of the Qinghai section of overlapping anomalies,and within 8 months after the occurrence of the anomalies.

关 键 词：玛多7.4级地震 地磁日变化 重叠异常 地磁异常 

分 类 号：P318.1[天文地球—固体地球物理学]