我国大陆中强地震前地电阻率异常的分析研究

ANALYSIS OF THE ANOMALIES IN GEOELECTRICAL RESISTIVITY BEFORE THE MEDIUM EARTHQUAKES WITH MAGNITUDE OF 5.1-6.9 IN CHINA

摘要:

本文处理分析了震级5.1-6.9的16个地震前后震中附近地电阻率观测资料和其他有关资料,发现ρ_s异常有效范围距震中在100公里左右;ρ_s异常表现下降(多数台ρ_s异常形态)或上升(少数)的趋势性变化形态;ρ_s异常持续时间的对数与震级之间的关系呈线性条带型。文中还讨论了ρ_s异常与震源应力场及其他前兆异常的一致性和ρ_s异常受地电年变化干扰影响的程度。

Abstract:

The data which were recorded in geoelectrical stations near the epicenters of 16 earthquakes with magnitude of 5.1-6.9 showed some features as following:
(1) The spatial scale of the anomaly was approximately 100km from the epicenters.
(2) Majority of the anomalies showed the decrease in the tendency of variation of ρ_s and minority of them increase.
(3) There is a linear functions in the coordinate of Lg△T-M(△T means the duration of the anomaly).
In addition, the relationship between the ρ_s-anomaly and the source-stress field as well as other precursors is discussed in the paper, and the problem of distinguishing between the ρ_s-anomaly and the annual change in ρ_s is also dealt with.