Joining Seismic Interferometry and a Migration Method to image Earth’s shallow structure

Abstract:

We develop a joint procedure to image the Earth’s shallow structure by combining seismic interferometry and a migration method. Based on seismic interferometry, auto-correlation function of tele-seismic wave would be equivalent to the reflected response of shallow structure below the station for a virtual source located at the station. In seismic interferometry, we first construct autocorrelograms of the seismic waves and then stack them at each station for events with different epicenteral distance, source depth and focal-mechanism. Such procedure yields a set of stacked auto-correlograms at each station, which can be viewed as a collection of reflected responses of the Earth’s shallow structure from a set of virtual sources at the locations of stations. We then apply a reverse time migration (RTM) method to image the shallow structure, using the stacked auto-correlograms. In RTM, the structure image is obtained by cross-correlation between wave field from sources and time-reversal wave field from receivers. In this presentation, we will show the concept of joint procedure, synthetic validations of recovering crust structure and possible applications in the real data.