近震前山西临汾、夏县中心地震台大地电场短临异常特征分析  

Analysis of Characteristic of Impending Anomalies on Geoelectric Field at Linfen and Xiaxian Central Seismological Stations before Local Earthquakes

作　　者：李艳[1,2] 高振强[3,2] 李军[1,2] 张仰辉[1,2] 

机构地区：[1]山西省地震局临汾中心地震台,山西临汾041000 [2]太原大陆裂谷动力学国家野外科学观测研究站,山西太原030025 [3]山西省地震局夏县中心地震台,山西夏县044400

出　　处：《山西地震》2013年第2期18-21,共4页Earthquake Research in Shanxi

基　　金：山西省地震局科研课题部分内容(SBK-1204)

摘　　要：通过分析山西临汾、夏县中心地震台大地电场在山西南部两次4级以上地震震前序列资料,发现2010年河津4.8级地震前,临汾、夏县两台站NS、NW测向记录到连续阶跃扰动图形,其EW向长短极距比值时间序列曲线出现变粗及大幅度双向快速变化异常;2009年陕西高陵4.4级地震前两台站EW测向长短极距比值出现大幅双向快速变化异常,根据电场多极距噪音识别原理分析,扰动图像应是震前电场异常的前兆信号,说明两台站地电场在山西南部2次4级多地震前有较好的短临异常反映。By analyzing a series of data of geoelectric field from Linfen, Xiaxian Central Seismological Stations before two earthquakes larger than M4.0 in southern Shanxi, it is found that continuous step disturbance appeared on NS and NW direction records at both Linfen and Xiaxian stations before the Hejin M4.8 earthquake in 2010. The EW direction time series curves of ratio of long to short polar distance substan- tially become thicker and amplitudes change up and down largely and rapidly in abnormal way before both Hejin both M4.8 earthquake in 2010 and the Gaoling, Shaanxi, M4.4 earthquake in 2009. By analysis according to the noise recognition principle for multi-polar distance geoeleetric field observation, it is inferred that the abnormal disturbance images should be precursory signals before the earthquakes, indicating that geoelectric field observations at both stations have better short - term anomaly reflects before two earthquakes larger than M4.0 in southern Shanxi.

关 键 词：近震 大地电场 长短极距比值 异常特征 

分 类 号：P315.722[天文地球—地震学]