同场地多方位多极距地电场相关特性  

Correlation characteristics of the geoelectric field with multiazimuth and multi-pole distance for the same field

作　　者：王玮铭 谭大诚[1,2] Wang Weiming;Tan Dacheng(Lanzhou Institute of Seismology,China Earthquake Administration,Lanzhou 730000,China;Earthquake Agency of Gansu Province,Lanzhou 730000,China)

机构地区：[1]中国地震局兰州地震研究所,中国兰州730000 [2]甘肃省地震局,中国兰州730000

出　　处：《地震学报》2020年第4期419-434,I0001,共17页Acta Seismologica Sinica

基　　金：国家重点研发项目(2018YFC1503206);中国地震局监测司2019年任务(zx1903006)共同资助。

摘　　要：针对5个典型地震震中周边的50余个场地记录到的地电场数据展开分析,计算了各场地不同方位之间的地电场相关系数δxy或同方位不同极距之间的地电场相关系数δxx,以此表征场地地电场变化的复杂性。结果显示:地震活动平静期间这些场地的地电场相关系数δxy和δxx具有相对稳定性,中强地震孕育发生期间震中附近多数场地的δxy和δxx会出现明显下降,且这种现象具有方向性、时间准同步性,并随着震中距的增加而逐步消失。从机理上推断,δxy和δxx的下降反映了震中附近局部场地地电场变化的非均匀性。At a given site,the correlation coefficientδxy between geoelectric field with different azimuths,orδxx between geoelectric field with differernt polar distances for the same azimuth can express the complexity of site geoelectric field variation.This paper analyzed the geoelectric field correlation coefficientδxy andδxx based on the geoelectric field data from more than fifty sites around five typical earthquake epicenters.The results show thatδxy andδxx of a site are relatively stable during a quiet period of seismic activity.During a moderate earthquake,theδxy andδxx for most of the sites near the epicenter decrease significantly.This phenomenon is directional and quasi-synchronous in time,and gradually disappears with epicentral distance increasing.Furthmore,in viewpoint of mechanism,it is deduced that the decrease inδxy andδxx reflects the non-uniformity of geoelectric field variation in the local sites near the epicenter.

关 键 词：地电场 多方位 多极距 相关性 

分 类 号：P315.722[天文地球—地震学]