地磁低点位移异常界线交汇现象与地震关系研究  

Relationship between the boundary intersection of geomagneticlow-point displacement anomalies and earthquakes

作　　者：杨兴悦 张飞捷 曾文浩 路晓辰 刘白云 YANG Xingyue;ZHANG Feijie;ZENG Wenhao;LU Xiaochen;LIU Baiyun(Gansu Lanzhou Geophysics National Observation and Research Station,Lanzhou 730000,Gansu,China;Upstream Hydrology and Water Resources Bureau of Yellow River Conservancy Commission,Lanzhou 730030,Gansu,China;Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China;Gansu Provincial Research Center for Conservation of Dunhuang Cultural Heritage,Dunhuang 736200,Gansu,China)

机构地区：[1]甘肃兰州地球物理国家野外科学观测研究站,甘肃兰州730000 [2]黄河水利委员会上游水文水资源局,甘肃兰州730030 [3]中国地震局兰州地震研究所,甘肃兰州730000 [4]甘肃省敦煌文物保护研究中心,甘肃敦煌736200

出　　处：《地震工程学报》2023年第4期926-932,共7页China Earthquake Engineering Journal

基　　金：甘肃省地震局地震科技发展基金(2018Y01);甘肃省敦煌文物保护研究中心开放基金(GDW2021YB13)。

摘　　要：利用国家地磁台网中心产出的观测资料,研究中国内地地区低点位移现象与强震之间的关系,认为地磁低点位移异常与强震之间具有较好的关联性。多次5级以上地震发生前两月内会出现一次或多次低点位移异常,地震往往发生在低点位移异常分界线300 km内。2022年1月8日青海门源6.9级地震、2016年1月21日青海门源6.4级地震和2019年9月16日甘肃肃南5.0级地震前两月内均出现了3次明显的地磁低点位移异常。将多次低点位移异常分界线叠加到同一幅图上,形成了1个或多个交汇区域,发现地震发生在低点位移分界线的交汇区域附近。综合活动构造断裂分布、历史大地震发生情况、中长期预测的强震潜在危险区及年度全国地震危险区进一步判断可能发震的区域,此项研究明显缩小了用地磁低点位移法预测地震发生地点的范围。The relationship between geomagnetic low-point displacement and strong earthquakes in the China's mainland was studied in this paper based on observation data from the national geomagnetic network center.A good correlation exists between the two aspects.One or more low-point displacement anomalies emerged within two months before numerous M>5 earthquakes,and the earthquakes usually occurred within 300 km of the boundary of low-point displacement anomalies.Four geomagnetic low-point displacement anomalies occurred two months before the Menyuan M 6.9 earthquake in Qinghai Province on January 8,2022.Meanwhile,three geomagnetic low-point displacement anomalies occurred two months before the Menyuan M 6.4 earthquake in Qinghai Province on January 21,2016,and the Ganzhou M 5.0 earthquake in Gansu Province on September 16,2019.One or more intersection regions will be formed when the boundaries of multiple low-point displacement anomalies are superimposed on the same graph.Results showed that the earthquakes occurred near the intersection region of low-point displacement boundaries.Possible earthquake regions can be determined by combining the distribution of active tectonic faults,the occurrence of large earthquakes in history,potential risk areas of strong earthquakes predicted in the medium and long term,and annual risk areas of earthquakes in China.This study markedly narrows down the prediction range of earthquake location with the geomagnetic low-point displacement method.

关 键 词：垂直分量 低点位移 低点时间 异常 

分 类 号：P315[天文地球—地震学]