P-SV-wave propagation in heterogeneous media: Velocity-stress distributional finite-difference method

Abstract

We have developed a 2D distributional-finite-difference (DFD) algorithm for modeling the propagation of seismic waves in heterogeneous media in the time domain. We revisit the classic staggered finite-difference algorithm by substituting the standard finite-difference operators with the recently introduced DFD operators with the methodological differences we underline. We find that the DFD operators improve the simulation accuracy while maintaining the simple structure of the finite-difference algorithm. Thanks to its weak formalism, the newly developed algorithm accurately and naturally accounts for the free surface, which is a substantial improvement for finite-difference approaches. Moreover, we develop an efficient factorization for the DFD operators. It limits the computational cost of the proposed algorithm to twice that of the finite-difference algorithm. Numerical examples demonstrate that the extra computational burden is well compensated by the superior accuracy of the DFD operators.