电阻率前兆异常指标研究

本文处理了云南及邻近地区1976年以来7次5.4—7.4级地震前后的电阻率观测资料。分析统计这些地震前电阻率异常时间、幅度和范围的结果表明,7级以上地震电阻率的长趋势异常时间为1—2年,异常幅度5%左右;短临异常时间1—2个月,最大异常幅度10.8%;最大异常范围290公里。6级地震的中期异常时间一般在1年以内,异常幅度2—6%,短临异常时间一般为1个月,异常幅度2.5—11.8%,最大异常范围220公里。5级地震无长趋势异常,短临异常时间一般为1个月左右,异常幅度3%左右,异常范围在220公里以内。

STUDYING THE ANOMALOUS INDEX OF RESISTIVITY PRECURSOR

The observational data of resistivity before and after the seven earthquakes (M = 5.4-7.4) occurred in Yunnan and the adjacent areas since 1976 was processed to study the anomalous time, amplitude and range of resistivity prior to the earthquakes in this paper. The results show that the time of long-term trend anomaly of resistivity of M>7.0 earthquakes is within 1-2 years; the anomalous amplitude 5 per cent or so; the short-term and impending anomalous time within 1 - 2 month; the maximum anomalous amplitude 10.8 per cent and the maximum anomalous range 290 km. Generally speaking, the medium-term anomalous time is within a year, the anomalous amplitude 2 -6 per cent; the short-term and impending anomalous time a month, the anomalous amplitude 2.5-11.8 per cent and the maximum anomalous range 220 km. There in no long-term trend anomaly of M=5.0 earthquake, usually, its short-term and impending anomalous time is a month or so, the amplitude 3 per cent and the anomalous range 200 krn.