Apply Seismic Migration Technique to Teleseismic Receiver Functions

Abstract:

Teleseismic receiver function method is an important technique to produce high-resolution images of deep earth structure. The Common Conversion Point (CCP) Stacking method exploits the P and S waves relative arrival time to locate subsurfaces, assuming that the structure beneath a station is locally horizontal, which is a proper approximation of the earth structure in most cases. However, for strongly laterally varying structure, the assumption can lead to artifacts in imaging. Nowadays, as more and more dense seismic array data become available, we can apply some exploration seismology techniques to image the deep earth structure. In this study we developed and tested several receiver function migration and imaging methods including the Kirchhoff wavefront migration (KM) technique and phase shift plus interpolation (PSPI) migration technique. Preliminary numerical tests show KM can correctly locate smoothly laterally varying subsurfaces. Artifacts appear if amplitudes of diffraction phase are large. For the PSPI migration method, we developed a new imaging condition scheme based on the adjoint operator theory. Updated results will be presented in the meeting.