河南及邻区5级以上地震前中等地震活动增强特征

Characteristics of the enhancement of activity of moderate earthquakes before M≥5 earthquakes in Henan Province and its adjacent areas

通过对河南及邻区 1 970～ 2 0 0 0年全部地震资料的系统处理 ,发现 5级以上地震前存在中等地震活动增强特征。经分析认为 :在本研究区域内 ,中等地震活动增强异常结束后 2年内发生 5级地震的概率为 0 .71 ;发震地点位于中等地震活动增强中的第一次、最后一次地震震中附近及其50 km内的概率均为 0 .86。其预测效能 R值评分为 0 .58。中等地震活动增强活动可以作为预测

In this paper, the enhancement of activity of moderate earthquakes before the M≥5 earthquakes in Henan province and its neighboring areas since 1970 has been studied. The study results show that: after anomaly for 2 years the probability of earthquake occurrence is 0.75. The distance between the earthquake location and the first or last epicenter of the enhancement of activity of moderate earthquakes is less than or equal to 50km, and its probability is 0.75. The error of prediction magnitude is from -0.5 to 0.5. The R-value is 0.68. The method shows better result of prediction.