3-D PHYSICAL MODELING AND PSEUDOSPECTRAL SIMULATION OF SEISMIC COMMON-SOURCE DATA VOLUMES

Numerical simulation of common-source seismic responses of arbitrarily complicated three-dimensional (3-D) variable-velocity structures is implemented by pseudospectral solution of the scalar wave equation. Potential applicability of such simulation to data analysis and interpretation is demonstrated by comparing synthetic 3-D (x, y, t) common-source gathers with those recorded on an areal grid of receivers over a physical scale model of a salt tongue. The iterative model adjustment process in fitting the physical model data is analogous to that which would be required for field data. Comparing differences between 2-D and 3-D synthetic responses allows interpretation of out-of-plane propagation. It is necessary to include the effects on the source directivity, because of a shield placed over the source during data acquisition, to numerically approximate the main features in the recorded scale model data.