Nearly perfectly matched layer method for seismic wave propagation in poroelastic media

The nearly perfectly matched layer (NPML) method has been successfully applied to electromagnetic and elastodynamic wave equations including elastic isotropic and anisotropic media types to absorb spurious arrivals reflected from introduced boundaries in a number of numerical solution methods. It has been shown to be extremely satisfactory for this purpose. In this paper, a first-order velocity-stress-pressure system with NPML is obtained from Biot’s equations. A staggered-grid finite-difference method with fourth-order accuracy in space and second-order accuracy in time is developed to simulate seismic wave propagation in a 2D fluidsaturated poroelastic media. The absorbing performance of NPML is investigated by wavefield snapshots, waveform and energy decay measurements in numerical experiments. The numerical results demonstrate that NPML suppresses the spurious reflections in a highly effective manner. ρ ρ λ μ μ α ( ) ( ) ( ) ∂ + ∂ = + ∂ ∂ + ∂ + ∂ ∂ u w