Earthquake hypocenter location using genetic algorithms

A new method for hypocenter location is proposed introducing some recent developments in global optimization techniques. The approach is based on the use of genetic algorithms to minimize some misfit criteria of the data. The method does not use derivative information and therefore does not require the calculation of partial derivatives of travel times of particular phases with respect to hypocentral parameters. The algorithm is illustrated with some synthetic examples using an actual local earthquake network. It is demonstrated how the initially random cloud of hypocenters quickly shrinks and concentrates sampling near the global minimum. Some simple new improvements to the basic algorithm are proposed to assist in avoiding local minima. -from Authors