弱震活动与续发性地震的可能关系

POSSIBLE CONNECTION BETWEEN WEAK SEISMIC ACTIVITY AND AN ENSUING STRONG EARTHQUAKE

大震后总有绵延多时的余震,大震前常有弱震活动增强现象。密集分布的弱震往往伴随有续发性强震。本文从弱震活动的能量关系上给出发生续发性地震的可能判据。并阐述了决定序列类型的余震活动所赖以存在的可能地质条件。

A strong earthquake is necessarily followed by a sequence of aftershocks and usually preceded by weak seismic activity of increasing magnitude. A sequence of weak earthquakes closely spaced in time is generally followed by an ensuing strong earthquake. In this paper, a possible criterion is derived on the basis of energy relation of the sequence of weak earthquakes for estimating the occurrence of the ensuing strong earthquake. Besides, it is also suggested that the possible geological structural condition with which the type of aftershock sequence may be related.