High-order Accurate Solution of Acoustic-Elastic Interface Problems on Adapted Meshes Using a Discontinuous Galerkin Method

Lucas Wilcox

Room: UNIV 101

Mar 14, 2012 2:30 PM EDT

Our goal is to develop scalable methods for global full-waveform seismic inversion. The first step we have taken towards this goal is the creation of an accurate solver for the numerical simulation of wave propagation in media with fluid-solid interfaces. We have chosen a high-order discontinuous Galerkin (DG) method to effectively eliminate numerical dispersion, enabling simulation over many wave periods. Our numerical method uses a strain-velocity formulation that enables the solution of acoustic and elastic wave equations within the same framework. Careful attention has been directed at the formulation of a numerical flux that preserves high-order accuracy in the presence of material discontinuities and at fluid-solid interfaces. We use adaptive mesh refinement (AMR) to resolve local variations in wave speeds with appropriate element sizes. To study the numerical accuracy and convergence of the proposed method we compare with reference solutions of classical interface problems, including Raleigh waves, Lamb waves, Stoneley waves, Scholte waves, and Love waves. We report strong and weak parallel scaling results for generation of the mesh and solution of the wave equations on adaptively resolved global Earth models.

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