Constraining relative source locations with the seismic coda

The relative location of seismic sources is of importance for the location of aftershocks on a fault, for the positioning of sources in repeat seismic surveys, and for monitoring induced seismicity. In this paper I show theoretically how the seismic coda can be used to infer a measure of the relative source location of two identical seismic sources from the correlation of the waveforms recorded at a single receiver. The theory is applicable to an explosive source in an acoustic or elastic medium, and for a point force or double couple in an elastic medium. For an explosive source the relative source location is constrained to be located on a sphere, while for a point force and a double couple the relative source location can be constrained to be located on an ellipsoid whose symmetry axis is determined by the point force or double couple.