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应用四川芦山MS7.0和汶川MS8.0震中周围部分地电场观测台站的资料,主要利用地电场波形比较和极化方位变化两种方法,并结合观测台站的工作日志,对两次地震前地电场观测资料进行了分析研究,并得出:芦山MS7.0和汶川MS8.0地震前部分台站地电场波形出现变异现象,主要表现为两种形式:日变波形的畸变(如盐源台和泸沽湖台)和相应时段地电场频谱特性出现变化,这些变异基本上出现在震前1~2个月内;利用两次地震前地电场观测的日均值计算了部分观测台站的地电场极化方位,发现在震前地电场的极化方位出现了大幅变化,最大变化幅度达160°,最小变化幅度也有10°;初步研究还发现,两次地震前夕,震中周围部分台站极化方位的正向或反向延长线,相汇集的区域与地震的震中有一定联系;对于研究所得结果,从地震电信号的产生机制和震源特性方面进行了尝试性理论解释.
Based on the data of some electric field observation stations around the epicenter of the Lushan MS7.0 and Wenchuan MS8.0 epochs in Sichuan Province, the earth-grid waveform comparison and polarization change are mainly used. Combined with the working log of the observation station, The results show that the waveform of geoelectric field in some stations before MS 7.0 of Lushan and Wenchuan MS8.0 earthquakes has the phenomenon of variation, which is mainly manifested in two forms: the distortion of diurnal waveform (such as salt The source stations and the Luguhu stations) and the corresponding time period, the variation of the electric spectrum of the electric field appeared. These variations basically occurred within 1 ~ 2 months before the earthquake. Using the daily mean value of the geoelectric field before the two earthquakes, It is found that there is a great change in the polarization direction of the electric field before the earthquake, with the maximum variation of 160 ° and the minimum variation of 10 °. Preliminary studies also found that on the eve of the two earthquakes, some stations around the epicenter The polarization direction of the positive or negative extension line, the convergence of the region and the epicenter of the earthquake have a certain relationship; for the study results, from the seismic electrical signal generation mechanism and source characteristics of the tentative theoretical explanation .