In order to effectively suppress the spurious reflections from the truncated boundaries in seismic numerical modeling, various perfectly matched layer (PML) absorbing boundary conditions have been developed in the past decades. The multi-axial perfectly matched layer (M-PML) attenuates seismic waves in the PML domain depending on the wave propagation directions, which remains efficient even under the situation of grazing incidences. To take advantage of the finite-element method (FEM) in dealing with the complex subsurface structure and irregular topography, we develop a nonconvolutional split-field M-PML based on the second-order elastic wave formulation to simulate the finite-element time-domain seismic wave propagation in this paper. The proposed M-PML algorithm requires fewer splitting terms and less storage space compared to the second-order M-PML in the literature. Three numerical experiments are carried out to illustrate the stability and efficiency of the newly proposed M-PML when used in the finite-element anisotropic elastic wavefield simulation with an irregular topography.
Citation: Li, H., Chen, J., Zhao, Z., & Li, J. (2021). A multi-axial perfectly matched layer for finite-element time-domain simulation of anisotropic elastic wave propagation. Journal of Seismic Exploration, 30, 173-200.