同场地多方位多极距地电场相关特性

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

  • 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δxyδxx 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δxyδxx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,δxyδxx的下降反映了震中附近局部场地地电场变化的非均匀性。

     

    Abstract: At a given site, the correlation coefficient δxy between geoelectric field with different azimuths, or δxx 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 coefficient δxy and δxx based on the geoelectric field data from more than fifty sites around five typical earthquake epicenters. The results show that δxy and δxx of a site are relatively stable during a quiet period of seismic activity. During a moderate earthquake, the δxy and δxx 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 in δxy and δxx reflects the non-uniformity of geoelectric field variation in the local sites near the epicenter.

     

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