2018年永清M_(W)4.3地震前后岩石圈磁场变化特征

Analysis of lithospheric geomagnetic field variation characteristics before and after the Yongqing M_(W) 4.3 earthquake in 2018

选取华北部分地区2016—2019年流动地磁矢量资料,分析2018年2月12日永清MW 4.3地震前后岩石圈磁场变化特征。结果表明,地震前岩石圈磁场变化异常特征显著,震后异常消失。在震前岩石圈磁场变化中,磁场的D、I、F、H、Z分量出现不同程度的异常特征,这些震前异常呈现出相同的、相似的变化趋势。在震前随着时间的不断累积,岩石圈磁场变化异常愈加显著,其中震前1.5年期各分量震磁异常显著。与震前相比,震后岩石圈磁场变化特征及趋势发生了较大改变。

Based on the mobile geomagnetic vector data from 2016 to 2019 in part of North China,this paper analyzed variation characteristics of the lithospheric magnetic field before and after the Yongqing MW 4.3 earthquake on February 12,2018.The results show that the anomalies of lithospheric magnetic field variation are significant before the earthquake and disappear after the earthquake.The D,I,F,H,Z components of the magnetic field observations have different degrees of anomalies in the variation of the lithospheric magnetic field before the earthquake and these anomalies show the same and similar variation trend.As time goes by before the earthquake,the anomalies of the lithosphere magnetic field variation become more and more significant.The seismo-magnetic anomalies of each component in the time span of 1.5 years before the earthquake are significant.Compared with that before the earthquake,the variation characteristics and trend of the lithosphere magnetic field change greatly after the earthquake.