阶段递进地震预报思路及其应用
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摘要
首先提供了 1998年 10月云南宁蒗 5 3级地震前所确认的孕震过程和主要前兆异常 ,以此为例阐述阶段递进的预报思路 ;这一预报思路首先根据历史震例中区域应力场的活动轨迹 ,跟踪其当前加载区域和活动构造 ,以被加载区域预释放大于 2倍均方差及 3 0～ 4 9级地震时空丛集图象确认孕震区的存在 ;以此孕震区为载体思考近源区各种前兆异常的内在相关性 ,利用发震概率计算模型和各种短临预报指标对发震概率P进行具体计算 ,以P≥ 0 5为短临预报阈值 ,从而在一定程度上克服孕震过程的可逆性和前兆场、源预报意义难辨所造成的虚报。
The seismogenic process and main precursor anomalies before the M5 3 Ninglang earthquake in Yunnan in October 1998 which have been affirmed are given first and then taking the Ninglang earthquake as example, the thinking about earthquake prediction in progress step by step is explouded as follows: first, based on active locus of regional stress field in historical earthquake examples, the current loaded area and active tectonics are traced; confirmation of seismogenic region is made if mean-square deviation with more than 2 times is released by the loaded area and there is piling up pattern of earthquakes with M3 0～4 9 in space and time and inner correlation among different precursor anomalies in near-source region is considered taking the seismogenic region as loading body; using calculation model for seismogenic probability and various short impending prediction indexes, seismogenic probability P is calculated and critical value of P≥0 5 for short-impending prediction is selected, thus eliminating false prediction to a certain extent caused by reversibility of seismogenic process and difficulty in distinction between precursor field and source from prediction sense.
The seismogenic process and main precursor anomalies before the M5 3 Ninglang earthquake in Yunnan in October 1998 which have been affirmed are given first and then taking the Ninglang earthquake as example, the thinking about earthquake prediction in progress step by step is explouded as follows: first, based on active locus of regional stress field in historical earthquake examples, the current loaded area and active tectonics are traced; confirmation of seismogenic region is made if mean-square deviation with more than 2 times is released by the loaded area and there is piling up pattern of earthquakes with M3 0～4 9 in space and time and inner correlation among different precursor anomalies in near-source region is considered taking the seismogenic region as loading body; using calculation model for seismogenic probability and various short impending prediction indexes, seismogenic probability P is calculated and critical value of P≥0 5 for short-impending prediction is selected, thus eliminating false prediction to a certain extent caused by reversibility of seismogenic process and difficulty in distinction between precursor field and source from prediction sense.
引文
〔1〕石绍先 ,付虹 ,沈斌 1988年澜仓—耿马大震的预报及再认识 西北地震学报 ,1991,13 (3) :35～ 40
〔2〕石绍先 景洪 5 3,5 4越南 7 0级地震预报 西北地震学报 ,1984,6 (3) :49～ 5 4
〔3〕石绍先 ,曹刻 澜仓 -耿马带大震 47年复发周期及其科学意义 地震研究 ,1999,2 2 (2 ) :116～ 12 1
〔4〕石绍先 ,邓志辉 云南 10次大震前地震活动分形研究 中国地震 ,1997,12 (4) :36 7～ 377
〔2〕石绍先 景洪 5 3,5 4越南 7 0级地震预报 西北地震学报 ,1984,6 (3) :49～ 5 4
〔3〕石绍先 ,曹刻 澜仓 -耿马带大震 47年复发周期及其科学意义 地震研究 ,1999,2 2 (2 ) :116～ 12 1
〔4〕石绍先 ,邓志辉 云南 10次大震前地震活动分形研究 中国地震 ,1997,12 (4) :36 7～ 377
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