A Study on SKS Wave Splitting Beneath the China Mainland and Adjacent Regions

Abstract

Abstract SKS wave splitting measurement is a powerful tool to characterize mantle deformation and study the dynamics and evolution of continents. We have made measurements of SKS wave splitting beneath the China mainland and adjacent regions. Our goal is to obtain the magnitude and orientation of upper mantle anisotropy and provide constraints for the evolution model of the crust and mantle. We use the technique of Silver and Chan to determine SKS wave splitting parameters at more than 80 three‐component broadband stations in China and neighboring regions, including the azimuths of fast polarization direction ( ϕ ) and delay times of split shear wave ( δt ). The fast wave polarization directions at most stations share a common preferred orientation in a same tectonic block. The fast axes show good correlation with the past and present‐day tectonic movement. Delay times range from 0.4s to 2.4s with an average about 1.2s. According to the splitting parameters of SKS wave, anisotropic characteristics in the study region are analyzed to investigate the dynamic process in the Earth.