Abstract
The wave-modes in isotropic elastic media are easy to get separated by using Helmholtz decomposition. This method, however, fails in TI (transverse isotropic) media due to the anisotropy, and more sophisticated operators are required. Most of these existing operators are implemented and limited in FD (finite-difference) stencil. We propose a Poynting-vector based method, which separates wave-modes pointwisely, independent of the modeling stencils. In TI media, the Poynting-vector indicates the group-velocity direction while the wave-modes get separated in the polarization-vector direction. We write the relationship between these two directions into a small numerical table by exploiting the phase-velocity direction as a bridge prior to wavefield propagation. During the modeling process, it is easy to estimate the group-velocity direction from the Poynting vector, and then we can get the polarization-vector direction to separate wave-modes by checking the numerical table. We test our method on several TI models. We furthermore apply our method to elastic reverse-time migration (RTM) in TI media.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 27-41 |
| Number of pages | 15 |
| Journal | Journal of Computational Physics |
| Volume | 381 |
| DOIs | |
| State | Published - Jan 5 2019 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: We are grateful to editor Jan S. Hesthaven, and two anonymous reviewers for improving the initial manuscript. We thank D. Keyes and D. Peter's supporting for the High-Performance Computing facilities. The research reported in this publication was in part supported by funding from King Abdullah University of Science and Technology (KAUST). For computer time, this research used the resources of the Information Technology Division and Extreme Computing Research Center (ECRC) at KAUST.