Joint Inversion of Receiver Function, Surface Wave Dispersion and ZH Ratio for Crustal Structure Based on Tikhonov Regularization

Abstract:

We proposed a joint iterative inversion method using receiver function, surface wave dispersion and ZH ratio data to better resolve 1-D crustal shear and compressional wave speed structure simultaneously. We implement a three-stage inversion strategy, which can take advantages of each dataset due to their complementary sensitivities to crust structures, to obtain structure information step by step using iterative linearized inversion approaches based on Tikhonov regularization of model parameters. We firstly invert surface wave dispersion and ZH ratio data to get 1-D shear velocity model, then incorporate P-wave receiver function data to obtain a much finer shear velocity model considering its high sensitivity to discontinuities. For the first two steps, the compressional velocity and density parameters are obtained from the shear velocity model using some empirical relationship. Finally, three datasets are further used to jointly invert for the compressional velocity structure based on the obtained shear velocity model. Synthetic tests show the superiority of joint inversion against separate inversion using only one or two datasets. They also demonstrate that the three-stage inversion strategy can make better use of different datasets to implement inversion physically and resolve finer crustal structure with more accuracy.