Feasibility study on 3D frequency-domain anisotropic elastic wave modeling using spectral element method with parallel direct linear solvers

International audienceA feasibility study on 3D frequency-domain anisotropic elastic wave modeling is conducted. The spectral element method is applied to discretize the 3D frequency-domain anisotropic elastic wave equation and the linear system is solved by parallel direct solvers, MUMPS andWSMP. A hybrid implementation of MPI and OpenMP for MUMPS is shown to be more efficient in flops and memory cost during the factorization. The influence of complex topography on MUMPS performance is negligible. With available resources, the largest scale modeling, 30 wavelengths in each dimension, is achieved. Using the block lowrank feature ofMUMPSleads to computational gains compared with the full-rank version. Limitation of MUMPS scalability for large number of MPI processes prompts us to investigate the performance of an alternative linear solver,WSMP. Preliminary comparison on small scale modelings shows a better scalability of WSMP while being more computational demanding