SVD enhanced seismic interferometry for traveltime estimates between microquakes

Abstract

In general, Green’s functions obtained with seismic interferometry are only estimates of the true Green’s function, introducing uncertainties to the information recovered from them. However, there are still many cases in which the source-receiver geometries are suitable for seismic interferometry, usually allowing the recovery of kinematic information. Here we show how to use the singular value decomposition to re-enforce the accuracy of traveltimes obtained from interferometric Green’s functions. We apply the combination of seismic interferometry and the singular value decomposition to obtain physically accurate inter-event traveltimes for microquake pairs at a geothermal reservoir. With a synthetic example, we show that the P-wave phase and coda-wave energy information are closer to correct with the singular value decomposition than without. These traveltimes could be used for velocity tomography and event location algorithms to obtain more accurate event locations and locally accurate velocity models.