Differential evolution algorithm in the earthquake hypocenter location

A novel global optimizing algorithm- Differential Evolution (DE) -has appeared recently. This method is easy and advantageous when used for kinematic location of the earthquake hypocenter. The motivation for implementing a robust (i.e., global and nonlinear) optimizing algorithm for the location problem is to obtain better results than those from the classical (i.e., linearized) approach (such as the FASTHYPO, WYPOELLIPSE, HYPOCENTER solutions, among others). Better solutions have lower final misfits expressed as the common L2 norm. The features of the DE algorithm are studied on a set of synthetic location problems. The DE procedure is controlled by 3 internal parameters, which are easy to adjust, and the convergence properties are very good. Location results using DE are compared with the HYPO71 solutions for real earthquake data from the Gulf of Corinth region, Greece. The DE results are significantly better. The DE optimizing algorithm seems to be very promising both for the location problem as well as for other problems in geophysics.