摘要
以四川省及其邻区31个地磁台2015年以来的垂直分量资料为研究对象,利用地磁加卸载响应比方法分析震前地磁日变化异常特征,结果显示:6组有效的地磁加卸载响应比高值异常中有5组异常对应了M5.0以上地震,异常多出现在震前6个月内;震中位于异常区边界线附近。分析认为地磁加卸载响应比高值异常是孕震区内局部地下电导率变化导致感应磁场发生改变的一种反映。
The geomagnetic vertical component data of 31 geomagnetic stations in Sichuan Province and its adjacent areas since 2015 were analyzed with the geomagnetic load-unload response ratio method.Results show six groups of high anomaly values of the geomagnetic load-unload response ratio.Five of these groups correspond to earthquakes above M5.0.The anomalies usually appear within 6 months before an earthquake,and the epicenter is located near the threshold line of the abnormal area.The high anomaly values of the geomagnetic load-unload response ratio are related to the changes in the induced magnetic field resulting from the electrical conductivity change in the seismogenic zone.
作者
何畅
芮雪莲
廖晓峰
邱桂兰
HE Chang;RUI Xuelian;LIAO Xiaofeng;QIU Guilan(Sichuan Earthquake Agency, Chengdu 610000, Sichuan, China)
出处
《地震工程学报》
CSCD
北大核心
2020年第2期431-437,共7页
China Earthquake Engineering Journal
基金
国家重点研发计划专题(2018YFC150330501)
中国地震局专项:全国地球物理台网数据跟踪分析与产出
四川省科技计划项目(2018JY0428)
震情跟踪定向工作任务(2019010402)。
关键词
地磁日变化
感应磁场
地磁加卸载响应比
geomagnetic diurnal variation
induced magnetic field
geomagnetic load-unload response ratio
