云南11组M_S≥6.5强震前h′值异常研究  

STUDY ON H′ VALUES ANOMALIES BEFORE 11 GROUPS OF M_S 6.5 STRONG EARTHQUAKES IN YUNNAN

作　　者：钱晓东[1] 和宏伟[1] 刘正荣[1] 

机构地区：[1]云南省地震局,云南昆明650041

出　　处：《西北地震学报》2004年第2期137-143,共7页Northwestern Seismological Journal

基　　金：中国地震局"十五"重点科研项目资助(100501-05-07).

摘　　要：利用极限时间法对云南省1970年以来MS≥6.511组强地震进行h′值计算,结果显示:11组强震前出现h′值异常,表现为不同程度的大幅(平均减幅达28%)突然减小现象,即地震活动出现异常平静的现象,可成为地震预报意见的关键指标;强震前出现8次地震活动增强-平静-主震的发震模式,占73%,出现3次增强-平静-增强(短期内)-主震的发震模式,占23%;h′值量板图对强震前的地震活动平静和地震活动增强现象展现得较为清晰;通过对11组强震进行预测,预测时间约为5个月。According to limit time method ,the h′ values of 11 groups of M_S6.5 strong earthquakes since 1970 in Yunnan province are calculated. The results show: h′ anomalies appeared before 11 groups of M_S6.5 strong earthquakes with sudden decrease of 28%(the average amplitude), meaning quiet anomaly of seismicity. It is the key index for make prediction. In 11 groups of strong event, 8 of the seismic process show the seismogenic mode of activation-quiet-main earthquake, which posses 73% of all; 3 are activation-quiet-activation(short-term)-main shock mode, which posses 23%; It was displayed clearly for quiet or activation of seismicity before strong earthquakes. Making forecasting to 11 groups of strong earthquakes suggests that forecast time is about 5 months.

关 键 词：强震 极限时间 h′值 归一化累积时间 

分 类 号：P315.75[天文地球—地震学]