【摘要】 研究了华北地区Ms≥5级地震平静、密集的韵律特征,以Ms≥5级地震平静时间超过30个月为异常背景,提出了该地区Ms≥6级地震发生前的定量预测指标:(1)当华北地区的Ms≥5级地震平静异常时间达到30个月时,该地区有发生Ms≥6级地震的危险性;Ms≥5级地震平静异常时间达到40个月时,发生Ms≥6级地震的危险概率为0.54,R值检验为0.12;Ms≥5级地震平静达到50个月时,发生Ms≥6级地震的危险概率为0.77,R值检验为0.22;(2)当华北地区的Ms≥5级地震平静异常结束后,3个月之内发生Ms≥6级地震的危险概率为0.38,R值检验为0.35;9个月之内发生Ms≥6级地震的危险概率为0.54,R值检验为0.44;15个月之内发生Ms≥6级地震的危险概率为0.69,R值检验为0.53。更多还原

【Abstract】 The characteristics in quietness and activeness for Ms≥5 earthquakes in North China are studied, and a quantitative index for the prediction of over Ms6 earthquake in the area is proposed under the background that the quietness of Ms≥5 earthquake is lasted more than 30 months.Index 1: when the quietness of Ms≥5 earthquakes lasted 30 months in North China, there is the risk of Ms≥6 earthquake; when the quietness of Ms≥5 reaches 40 months, the risk increases further, and the probability of occurrence is 0.54, the R-value is 0.12; when the quietness of Ms≥5 is up to 50 months, the risk probability gets to 0.77 and the R-value is 0.22.Index 2: when the seismic quietness of Ms≥5 in the North China area ends, the risk probability for the occurrence of a Ms≥6 earthquake in 3 months is 0.38 and the R-value is 0.35, the risk probability for the occurrence in 9 months is 0.54 and the R-value is 0.44; the risk probability in 15 months is 0.69 and the R-value is 0.53.更多还原