唐山7.8级地震短临前兆场源特征的研究

为了通过场的动态监视和源的过程追踪以实现地震预报,以唐山7.8级地震为例,研究了震前各种前兆方法观测到的短临异常的场兆和源兆的特征。通过研究得出:场兆数量多、密度小、异常台项比低,源兆数量少、密度大、异常台项比高;台点多的地下水位和流动重力较易区分场兆和源兆的差异性;源兆主要分布在一些断裂构造形成的闭锁区内,场兆主要分布在闭锁区附近一些活动断裂及交汇部位。

STUDY ON FIELD-SOURCE CHARACTERISTIC OF SHORT-IMMEDIATE PRECURSOR OF TANGSHAN EARTHQUAKE OF Ms=7. 8

The characteristic of field and source precursors of short-immediate anomalies of Tangshan earthquake (As=7. 8, 1976) observed by various manners have been studied in order that field dynamic and source process are traced to realize earthquake prediction. It is concluded that field precursory numbers are many, but its dense is small, anomalous station-item ratio is low, source precursory numbers are a few, but its dense is large, anomalous station-item ratio is high; and it is easy that difference between field and source precursors is discriminated using data of groundwater level and mobile gravity survey in many station areas; the source precursors locate mainly in locking area of rupture structure, and the field precursors locate mainly in active ruptures and their cross position near the locking area.