弥渡台地电场震前线性极化异常分析

Analysis on Linear Polarization Pre-earthquake Anomalies of Geoelectric Field at Midu Seismic Station

分析了弥渡台地电场自2007年以来的的观测资料,分别针对省内及周边地区4次5级以上地震前NS与EW向测值的矢量方向性变化,进一步作线性异常关系分析,包括拟合直线及线性相关性的异常。结果表明,在地震发生前3—6个月,地电场会出现明显的线性极化特征。线性极化异常具有非常典型的短临性,对未来地震预测有一定的参考价值。

In this paper,geoelectric field data recorded by Midu seismic station since 2007 are analyzed aiming at pre-earthquake vector directional changes of NS and EW direction before 4 M≥5.0earthquakes occurred in Yunnan province and its surrounding areas using straight line fitting and linear correlation methods.The result shows that the polarization of geoelectric field gradually become linear during 3~6months before earthquakes,which may be a kind of typical short-impending pre-earthquake anomaly and has significance for earthquake prediction.