利用地震矩张量反演鲜水河断裂带现今运动学特征

INVERSlON OF THE PRESENT KINEMATIC CHARACTER ISTICS OF XIANSHUIHE FAULT ZONE FROM SEISMIC MOMENT TENSOR

本文探讨了利用地震矩反演断裂形变带运动学参数的基本理论和方法，将其初步应用于鲜水河断裂形变带变形分析和运动机制的研究。结果表明，鲜水河断裂带呈现出走向拉伸、倾向压缩的形变格局，由地震矩反演的断裂带剪切形变速率（１０．９ｍｍ／ａ）与用地质学估算方法（１７ｍｍ／ａ）和现今地壳形变测量（８ｍｍ／ａ）的结果相当。同时，反演出的应变主方向能解释鲜水河断裂现今活动分段性特征以及多种滑动方式共存的现状，从而证明该方法是目前研究区域运动学问题切实有效的手段之一。

In this paper the theory and method for inversing the kinematic parameters of a fault zone and preliminarily apply them to study the deformation and its mechanism of Xianshuihe Fault Zone are discussed. The results show that Xianshuihe Fault Zone is generally extensive in the strike direction and compressive in the dip direction,and the shear velocity(10.8mm/a)is consistent with the results obtained from geology (17mm/a) and present crustal deformation measurements(8mm/a).The estimated main strain directions can be used to explain the active characteristics and co-existence of multislip ping mode of this zone. It is indicated that the method is one of practical ways for studying the regional kinematic problems.