复杂大地震分析和龙陵地震震源过程

本文发展了Kikuchi和Kanamori的P波反演方法,使之适应于多断层活动和破裂在断层面上沿任意方向传播的情况,并用来研究了1975年5月29日龙陵第一大震的震源过程。结果表明,该震是由一个以走滑错动为主的主断层（走向150°）和另一个走向相同但作垂直倾滑错动的次断层同时活动引起的。在主断层和次断层上分别分布有6个和4个子地震。这种多重破裂和破裂传播的方向性效应,使龙陵地震P波波形和震源过程非常复杂。

ANALYSIS OF COMPLEX EARTHQUAKES AND SOURCE PROCESSES OF LONGLING

In this paper, Kikuchi and Kanamori's inversion method on the complex body waves was modified to cover the following: the subevents with geometry parameters of an added minor fault can distribute along the strikes of either the major fault or the minor fault; the rupture direction on the fault plane can be arbitrary.This technique was applied to the 29 May 1976, Longling earthquake （the first one）. The results show that this event was caused by the activities of a nearly strike-slip major fault with strike 150° and a vertically dip-slip minor fault with the same strike. About 10 sub-events （6 occurred on the major fault and 4 on the minor fault） and the rupture directivity brought about the very complex P waveforms. Compared with its not very large magnitude, Longling earthquake is an unusually complex one.