Anisotropic Layering and Seismic Body Waves: Deformation Gradients, Initial S-Polarizations, and Converted-Wave Birefringence
Abstract
We apply an updated computer algorithm for reflectivity synthetic seismograms to examine observational scenarios for seismic plane-wave propagation through horizontally stratified anisotropic media. Based on the commercial software package Matlab, the ANIMATIVITY software can compute synthetic seismograms using anisotropic models described either by a full elastic tensor or using common notations for an elastic tensor with a symmetry axis. This algorithm enables us to simulate wave propagation with high frequency components and to consider all transmission and reflection coefficients in one step. We validate the ANIMATIVITY code with synthetic P–S receiver functions in layered anisotropic media, compared against legacy reflectivity codes. Contrasting synthetic RFs for models with either sharp or gradual anisotropy transitions, we observe features in the gradual-transition models that could be misconstrued as caused by dipping interfaces. We find that S–P receiver functions have the potential to constrain anisotropy at depth via the back-azimuth variation of Sp-phase amplitude on the vertical component. We conclude that practical use of S receiver functions to investigate anisotropy will depend on accurate determination of the initial S-wave polarization. The ANIMATIVITY simulations of shear-wave splitting include S–P converted waves that precede the split SKS wave.
Publication Title
Pure and Applied Geophysics
Recommended Citation
Chen, X., Park, J., & Levin, V. (2021). Anisotropic Layering and Seismic Body Waves: Deformation Gradients, Initial S-Polarizations, and Converted-Wave Birefringence. Pure and Applied Geophysics, 178 (6), 2001-2023. https://doi.org/10.1007/s00024-021-02755-6
