Elastic modeling in 3D tilted transversely isotropic (TTI) media with convolutional perfectly matched layer (CPML) boundary conditions

Abstract

To simulate wave propagation in a tilted transversely isotropic (TTI) medium, we developed a three-dimensional (3D) elastic forward modeling algorithm with staggered-grid finite-difference method in time domain. To remove the artificial reflections efficiently at the model boundary, we derived the convolutional perfectly matched layer (CPML) absorbing boundary conditions for a TTI medium. In this paper, numerical experiments indicate that elastic wave propagation is well simulated and CPML boundary conditions efficiently remove artificial reflections in the 3D TTI medium. The S-wave split is clearly shown caused by the tilted orientation of the anisotropy which is determined by a dip and strike in 3D medium. In addition, through parallelization of the model space in z-direction with message passing interface (MPI), we can dramatically reduce the computation time and required memory.