Accurate simulations of nonlinear dynamic shear ruptures on pre-existing faults in 3D elastic solids with dual-pairing SBP methods

TL;DR

This paper develops and analyzes stable, accurate numerical methods using dispersion relation preserving SBP finite difference operators for simulating nonlinear dynamic shear ruptures on complex 3D faults, improving accuracy and efficiency.

Contribution

The paper introduces dispersion relation preserving SBP FD operators that eliminate spurious high frequency modes, enhancing simulation accuracy for nonlinear earthquake ruptures in 3D elastic solids.

Findings

DRP SBP FD operators improve numerical dispersion accuracy

The method accurately reproduces benchmark dynamic rupture problems

Achieves better accuracy with less computational effort

Abstract

In this paper we derive and analyse efficient and stable numerical methods for accurate numerical simulations of nonlinear dynamic shear ruptures on non-planar faults embedded in 3D elastic solids using dual-paring (DP) summation by parts (SBP) finite difference (FD) methods. Specifically, for nonlinear dynamic earthquake ruptures, we demonstrate that the DP SBP FD operators [K. Mattsson. J. Comput. Phys., 335:283-310, 2017] generate spurious catastrophic high frequency wave modes that do not diminish with mesh refinement. Meanwhile our new dispersion relation preserving (DRP) SBP FD operators [C. Williams and K Duru, arXiv:2110.04957, 2021] have more accurate numerical dispersion relation properties and do not support poisonous spurious high frequency wave modes. Numerical simulations are performed in 3D with geometrically complex fault surfaces verifying the efficacy of the method. Our method accurately reproduces community developed dynamic rupture benchmark problems, proposed by Southern California Earthquake Center, with less computational effort than standard methods based on traditional SBP FD operators.