Joint Inversion of Crustal and Uppermost Mantle Structure in Western China

Abstract

Abstract : This research is to develop joint-inversion methods involving P travel times, receiver functions, and surface wave dispersion measurements and to apply them to the western China region to obtain 3D models of P and S structures of the crust and upper mantle. We successfully implemented a search-based algorithm (neighborhood algorithm) for joint inversion of surface wave dispersion data, receiver functions, and Pn delay time. The implementation uses parallel programming with MPI calls, making massive data processing possible. We have systematically carried out individual components of the project, obtaining unprecedented data sets for surface wave dispersion, receiver functions, and Pn tomography, needed for the joint inversion. We have tested the joint inversion method and proposed a practical strategy for the joint inversions of the real data. We obtained detailed joint inversion results for the dense Hi-Climb array, which are generally consistent with previous results but show considerable difference in details (crustal structure and Moho depths). We have performed systematically joint inversions of all available stations in western China and obtained 3D S velocity model, average crustal Vp/Vs map, and derived 3D P velocity model of the region.