2020年10月15日地磁垂直强度极化异常与玛多M7.4地震  

GEOMAGNETIC VERTICAL COMPONENT POLARIZATION ANOMALY IN OCTOBER 15TH 2020 BEFORE MADUO M7.4 EARTHQUAKE

作　　者：冯丽丽 管贻亮[3] 樊文杰 贺曼秋[5] 李霞 何畅 廖晓峰[6] 艾萨·伊斯马伊力[7] 袁文秀 刘素珍 冯志生 FENG Lili;GUAN Yiliang;FAN Wenjie;HE Manqiu;LI Xia;HE Chang;LIAO Xiaofeng;Aisa·Yisimayili;YUAN Wenxiu;LIU Suzhen;FENG Zhisheng(Geodynamics Field Observation and Research Station of Qinghai-Tibet Plateau,Golmud 810001,China;Qinghai Earthquake Agency,Xining 810001,China;Shandong Earthquake Agency,Ji'nan 250014,China;Yunnan Earthquake Agency,Kunming 650224,China;Chongqing Earthquake Agency,Chongqing 401147,China;Sichuan Earthquake Agency,Chengdu 610041,China;Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830001,China;Zhejiang Earthquake Agency,Hangzhou 310013,China;Shanxi Earthquake Agency,Taiyuan 030021,China;Jiangsu Earthquake Agency,Nanjing 400071,China)

机构地区：[1]青海格尔木青藏高原内部地球动力学野外科学观测研究站,青海格尔木810001 [2]青海省地震局,青海西宁810001 [3]山东省地震局,山东济南250014 [4]云南省地震局,云南昆明650224 [5]重庆市地震局,重庆401147 [6]四川省地震局,四川成都610041 [7]新疆维吾尔自治区地震局,新疆乌鲁木齐830001 [8]浙江省地震局,浙江杭州310013 [9]山西省地震局,山西太原030021 [10]江苏省地震局,江苏南京400071

出　　处：《高原地震》2021年第4期1-6,共6页Plateau Earthquake Research

基　　金：地震科技星火计划“地震地磁垂直强度极化异常空间特征研究”(项目编号:XH20062);青海格尔木青藏高原内部地球动力学野外科学观测研究站专项课题“青藏高原岩石圈磁场特征分析”联合资助。

摘　　要：利用地磁垂直强度极化法对2020年1月至2021年5月期间中国大陆西部的磁通门磁力仪秒采样观测资料开展了5~100 s频段的极化分析。发现2020年10月15日出现一次异常,高值出现的地震台站集中在甘肃、青海、四川、重庆、广西等地,插值后的空间分布图中形成一个大范围高值异常区,从青海中部一直延伸至了广西北部。同时,对Kp指数与Dst指数的调查结果表明异常期间为外源场弱活动时段。异常出现219天后发生了玛多M7.4级地震,震中位于高值异常区边界线附近。The geomagnetic vertical intensity polarization method was used to analyze the polarization value of 5 to 100 s frequency bands of the second sampling data onto the fluxgate magnetometer in the western part of the Chinese mainland from January 2020 to May 2021.A seismic magnetic disturbance anomaly appeared on October 15,2020,and high-value stations were concentrated in Gansu,Qinghai,Sichuan,Chongqing,Guangxi and other places.The interpolated spatial distribution maps formed a large range of high-value anomaly areas,extending from the middle of Qinghai to the north of Guangxi.The results of Kp index and Dst index show that the abnormal period is the period of weak activity of exogenous field.The Maduo M7.4 earthquake occurred 219 days after the occurrence of the anomaly,with the epicenter located at the boundary of the high-value anomaly area.The process of anomaly analysis and tracking is of great practical significance to the seismic tracking in the western part of China's Mainland.

关 键 词：玛多M7.4地震 地磁垂直强度极化 高值异常 

分 类 号：P315.721[天文地球—地震学]