• 责任者：An Zhanghui (Lanzhou Base of Institute of Earthquake Prediction ; CEA ; Lanzhou 730000 ; China) ; Du Xuebin
• 刊名：Chinese Journal of Geophysics
• 出版年：2013
• 卷期：56(11)
• 关键词：汶川地震2008 ; Wenchuan earthquake 2008 ; 地电场 ; geoelectric field ; 四川 ; Sichuan Province
• 页码：p.3868-3876
• 图表：4 illus., 1 table, 38 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

     Applying the data of geo-electric field observation stations surrounding the epicenter of Sichuan Lushan Ms7. 0 and Wenchuan Ms8.0 earthquake, mainly using electric field waveform comparison and polarization orientation changes of two kinds of methods, and combining the observation log of station, we study and analyze the data of the geo-electric field stations before the two earthquakes and conclude that, the anomalous waveform variation before the Lushan Ms7.0 and Wenchuan Ms8.0 earthquake showed mainly two forms： diurnal waveform distortion （such as Yanyuan station and Luguhu station） and the change of geo-electric field frequency spectrum characteristics in the corresponding time, and these variations basically appeared in 1-2 months before the earthquake. Using the daily mean value of geo-electric field observed by part of stations around the epicenter of two earthquakes, we calculated the polarization of geo-electric field before two earthquakes, and found a sharp change in the polarization direction before the earthquake, the largest change was 160°, and minimum change 10°. A preliminary study also found that, before the two earthquakes, the intersection region and the epicenter seems to have some sort of connection, the intersection region formed by polarization orientation forward or reverse extension line; for the results obtained in this study, a tentative theoretical explanation from the generation mechanism of seismic electric signals and the focal mechanism of the two earthquakes.