2D FINITE-DIFFERENCE ELASTIC-WAVE MODELING INCLUDING SURFACE-TOPOGRAPHY

A 2D numerical finite-difference algorithm accounting for surface topo graphy is presented. Higher-order, dispersion-bounded, cost-optimized finite-difference operators are used in the interior of the numerical grid, while non-reflecting absorbing boundary conditions are used alon g the edges. Transformation from a curved to a rectangular grid achiev es the modelling of the surface topography. We use free-surface bounda ry conditions along the surface. In order to obtain complete modelling of the effects of wave propagation, it is important to account for th e surface topography, otherwise near-surface effects, such as scatteri ng, are not modelled adequately. Even if other properties of the mediu m, for instance randomization, can improve numerical simulations, incl usion of the surface topography makes them more realistic.