临汾大地震前地震活动异常特征及其机理探讨  

The Anomalous Characteristics of Seismicity of Linfenfen Earthquake and its Mechanism Study

作　　者：宋治平[1] 梅世蓉[1] 

机构地区：[1]国家地震局分析预报中心,国家地震局地球物理研究所

出　　处：《山西地震》1995年第3期99-106,共8页Earthquake Research in Shanxi

摘　　要：本文运用丰富的地震历史资料，采用长时间大范围的思路对１６９５年临汾大地震前的活动场进行了剖析，发现临汾大地震前表现出很强的活动异常特征：临汾地震前环绕主震震中形成一个ＮＥ向的长６００ｋｍ的椭圆形环形分布图象；在孕震过程中，增强区内的地震活动可分为３个强弱不同的阶段，空间的不均匀性（震丛率、有震面积率以及蠕变释放率等）也不同；并且在巨震前地震活动增强区内的活动性主要表现为短周期成分，在正常阶段出现的长周期却消失。然后运用二维圆形硬包体模型对这些特征进行了初步解释，这对其它巨大地震的研究以及未来巨大地震的预测都具有重要意义。Seismicity field before Linfen macroquake of 1695 has studied by using the analysis method of long timeand great range and the abundance earthquake historic data,the abvious anomalous characteristics have beenshown.A 600 km long and NE striking elliptic ring distribution of earthquakes formed around the epicentreof the major shock before Linfen earthquake. In the process of earthquake preparation,the activity in the seis-micity enhanced region may be divided into three strength different stage,and the spatial non─homogeneityis also different,for example earthquake cluster rate;earthquake occurrence area rate; creep release rate andso on. The activity in the seismicity enhanced region mainly showed short-period,and the long-period inthe normal stage disappeared. Then we have discussed these anomalous characteristics by using the model oftwo-dimensional circular hard inclusion. This will have an important place in the study of other great earth-quakes and the prediction of great earthquakes.

关 键 词：异常特征 大震 地震活动性 临汾地震 

分 类 号：P315.5[天文地球—地震学]