Interferometric imaging of the underside of a subducting crust



Seismic interferometry provides tools for redatuming physical data to a new source location. Turning a source, located close to a structure of interest, into a virtual receiver has the potential benefit of improving the quality of imaging by increasing the effective aperture and mitigating the effect of velocity uncertainty in the overburden. Here, we consider the problem of estimating the Green’s function between two earthquakes located inside a subducting slab using earthquake data recorded at the surface. Our primary focus is to obtain an accurate time-image of the subducting interface. We propose a novel two-step kinematically correct redatuming procedure that first redatums the data from earthquakes below the subducting interface to the surface via classical interferometry, and then utilizes source–receiver wavefield interferometry to redatum virtual surface seismic data to the location of a particular earthquake event.