大地电磁在地震预报中的应用

APPLICATION OF MAGNETOTELLURIC TO EARTHQUAKE PREDICATION

论述了大地电磁 (MT)地震前兆多参数综合分析方法和扩展膨胀各向异性 (EDA)电性前兆识别。不同的 MT参数以不同的形态特征和方式 ,从不同侧重面反映地球电导率结构特征 ,充分利用包含于各参数内的信息 ,对它们随时间的变化进行综合分析研究有利于更可靠地判断新出现的 MT前兆。 EDA电性前兆是由孕震期间深部原地应力场的变化引起的 ,可能出现在一个较大的地域范围内 ,因而该前兆是一种具有很好应用前景的地震前兆 ,利用 MT法进行监测较为有利。

The predication of earthquakes by using MT has definite physical mechanism,and international features.This paper discusses multiple parameters comprehensive analytical method about magnetotelluric(MT) earthquake precursor,and the electrical precursor of extensive dilatancy anisotropy(EDA).Different MT parameters inflect the conductivity structural characteristic of the earth in different features and ways from different sides.The utilization of the information included in every parameters,and comprehensively studing and analyzing their variations with time contributes to reliable judgment of the latest appearing MT precursor.While the electrical precursor of EDA is caused by the variations of deep in situ stress field in the development of earthquakes,which may appear in considerable extensive regions,so the deep electrical variations of EDA has a fairly good application prospect,and is thus beneficial for utilizing MT to monitor earthquake.