江宁地电台地电阻率日变形态特征与短临畸变异常

ANALYSIS ON DAILY VARIATION SHAPE FEATURE OF GROUND RESISTIVITY AT JIANGNING GEOELECTRIC STATION AND THE SHORT-IMPENDING DISTORTION ANOMALY

摘要:

江宁地电台使用ZD-8数字地电仪观测以后,记录到了地电阻率测值每日呈准“一峰一谷”的方波形周期变化。本文描述了日周期变化形态,使用时距平方法研究分析了日变化的季节特征和时间特征。在1991年9月12日江宁小丹阳3.1级地震(Δ＝34km)和1992年10月22日射阳4.6级地震(Δ＝244km)前,地电阻率日变形态消失,地震10多天后日变又恢复,出现明显的短临前兆。

Abstract:

The periodic change of ground resistivity, which appears the square wave of‘one peak and one valley 'every day, is recorded by DZ-8 digital terrameter at Jiangninggeoelectric station. This paper describes the daily period-variation shape,and analyses the seasonal features and temporal features of daily variation by using time-distance square method. Be-fore the Xiaodanyang earthquake,Jiangning (M3.1,Δ=34km) on Sep.12,1991 and the Sheyang earthquake (M4.6,Δ=244km) on Oct.22,1992,the daily variation shape of ground resistivity disappeared,ten plus days after the earthquakes,the daily variation re-covered,showing obvious short-impending precursor.