用于地震定位的SAMS方法

HYPOCENTRAL DETERMINATION USING SIMULATED ANNEALING METHOD

由于地震定位受发震时刻与震源深度间强烈的折衷关系的困扰及反演问题的非线性影响 ,该问题一直未得到根本解决 .为此 ,本文提出了一种新的定位方法———SAMS法 ,该方法利用走时残差和到时残差之绝对值极小作为目标函数 ,用快速模拟退火法求解反演问题的解答 .并将该方法用于 1 999年 9月 2 1日台湾集集地震的再定位 ,其结果与其他方法相比 ,SAMS方法不仅降低了发震时刻与震源深度间的折衷关系对定位结果的影响 ,而且其定位结果具有很高的稳定性和分辨率 .

Because of the strong trade off between the assumed origin time and focal depth and the nonlinearity of the inversion problems, the earthquake location is a basic issue in seismology which is not settled at all. Aimed at the problem, this article presents a new earthquake location method, named SAMA method. In this method, the objection function is the absolute values of the remnants of travel times together with the arrival times, and the Fast Simulated Annealing method is used to inverse. Applying this method to the Chi Chi event occurred in Taiwan on Sep 21, 2000, we show that the SAMS method not only reduce the effects of the trade off between the origin time and focal depth, but also can get better stability and resolving power.