A High-Order Finite-Difference Method on Staggered Curvilinear Grids for Seismic Wave Propagation Applications with Topography

Ossian O'Reilly, Te-Yang Yeh, Kim B. Olsen, Zhifeng Hu, Alexander N. Breuer, Daniel Roten, & Christine A. Goulet

Published August 4, 2021, SCEC Contribution #11159

We developed a 3D elastic wave propagation solver that supports topography using stag-gered curvilinear grids. Our method achieves comparable accuracy to the classical fourth-order staggered grid velocity–stress finite-difference method on a Cartesian grid. We show that the method is provably stable using summation-by-parts operators and weakly imposed boundary conditions via penalty terms. The maximum stable timestep obeys a relationship that depends on the topography-induced grid stretching along the vertical axis. The solutions from the approach are in excellent agreement with verified results for a Gaussian-shaped hill and for a complex topographic model. Compared with a Cartesian grid, the curvilinear grid adds negligible memory requirements, but requires longer simulation times due to smaller timesteps for complex topography. The code shows 94% weak scaling efficiency up to 1014 graphic processing units.

Citation
O'Reilly, O., Yeh, T., Olsen, K. B., Hu, Z., Breuer, A. N., Roten, D., & Goulet, C. A. (2021). A High-Order Finite-Difference Method on Staggered Curvilinear Grids for Seismic Wave Propagation Applications with Topography. Bull. Seis. Soc. Am., 112(1), 3-22.