震情过程追踪与发震时间的综合概率预报

基于大震前主破裂潜在变化的过程中产生出小震活动、地壳形变异常以及伴随地壳形变而产生出的地下水、水化学、地电阻率等前兆现象随时间变化显示出的动态异常图象，依据河北省及周围地区１９７０年至１９８８年的中强震前的前兆异常资料的研究，提取出了９个前兆异常因子的异常变化规律及特征，并建立了务因子的概率预报模型，同时计算出相应的前兆发生后不同时段内地震发生的概率。最后在多个因子随时间推移而逐次出现前兆异常的情

TRACING FOR EARTHQUAKE SITUATION AND SYNTHETIC PROBABILITY PREDICTION FOR EARTHQUAKE OCCURRENCE TIME

The microearthquakes' activities before the fracture of the main quake,the dynamic anomaly images of crustal deformation anomalies and its concomitant precursors of underground water,hydrochemistry and earthresistivity are analyzed.The precursory anomaly data before some medium and strong earthquakes in Hebei province and its vicinity from 1970 to 1988 are studied.Based on the above study we extracted the variation character of 9 precursory anomaly factors,established the probability prediction model with each factor,and calculated the probability of earthquake during the different stage after a precursor took place.At the end,under the circumstance of the precursors taking place one by one with time,using equation(9) we calculated the synthetic probability of each kind(A,B,C)anomaly and its variation with time.The time stage that synthetic probability value was relatively high is choosed as occurrence time of potential earthquakes.The method was test in the paper.The results show that the synthetic probability high values of precursors were basically consistent with earthquake occurrence time.The results in this paper are significant to tracing prediction in long term,medium term and short term.