STRATIFIED CRUSTAL ANISOTROPY FROM RECEIVER FUNCTION AND ITS PARTICLE SWARM INVERSION

Abstract

Crustal anisotropy at multiple depths is essential for studying the vertical variation of crustal deformation. Due to the complexity of the crust, mapping the crustal anisotropy at different depth from teleseismic receiver function (RF) is an ongoing subject that requires further studies. Based on the previous works, this paper goes further to discuss the RF wavefield pattern of stratified crustal anisotropy by means of the generalized reflection and transmission coefficients method, which provides us a new theoretical basis for understanding the RF data with stratified anisotropic crustal models. In addition, we develop a global inversion method for extracting stratified anisotropic models based on the particle swarm algorithm. The test results from both numerical and real data show that, our method can correctly recover the depth-dependent anisotropic parameters from the RF data and distinguish different anisotropic layers of the crust, as long as isotropic velocity model is well determined. Noise suppression in data processing via curvelet transform is useful for the analysis of crustal anisotropy.