同场地多方位多极距地电场相关特性

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δ_xy或同方位不同极距之间的地电场相关系数δ_xx，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δ_xy和δ_xx 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δ_xy和δ_xx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，δ_xy和δ_xx的下降反映了震中附近局部场地地电场变化的非均匀性。 

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

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