Hypocentral determination using simulated annealing method

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.