An efficient method for joint hypocenter determination for large groups of earthquakes

The number of seismic events that can be located simultaneously by the Joint Hypocenter Determination method is limited generally by the amount of computer time and computer memory available. To find directly the hypocenters of M earthquatkes and the station corrections to N stations requires solving a system of 4M + N equations in 4M + N unknowns. This paper presents a method of solving this system of equations which is considerably more efficient than Guassian elimination.