Two-dimensional elastic wave modeling with surface topography using a weighted-averaging finite-element method

Abstract

Surface topography has a significant influence on seismic wave propagation in a reflection seismic exploration. Effects of surface topography on twodimensionalelastic wave propagation are examined through modeling using a weighted-averaging (WA) finite-element method (FEM). This method has proven to be more computationally efficient than conventional FEM. First, effects of an air layer on wave propagation are investigated using flat surface models with andwithout the air layer. To verify correctness and efficiency of our scheme, we compare WA FEM results for irregular topographic models with those derived fromgeneral FEM using one set of rectangular elements. Using irregular surface topography models, elastic wave propagation is investigated to show that the breaks in slope act as a new source for diffracted waves and Rayleigh waves are more seriously corrupted by surface topography than P-waves.