A comparison of two sets of synthetic reflection seismograms for a complex two‐dimensional model of the oceanic crust‐mantle transition

Abstract

The algorithm chosen for the calculation of synthetic seismograms often represents a compromise between the realistic representation of complex geology and economy. Comparison of synthetic seismic reflection sections calculated using a relatively inexpensive ray theory and a relatively expensive generalized reflectivity algorithm for a complex, laterally inhomogeneous model of the oceanic Moho demonstrates that ray theory provides a close approximation to the full‐wave theory. The chief difference between the two synthetic sections is the more accurate variation in amplitude with horizontal range predicted by the reflectivity synthetics, due to its inclusion of the horizontal smoothing of the reflected amplitudes over the width of the First Fresnel Zone. While this Fresnel zone smoothing will become increasingly important with increasing reflector depth, the results shown here suggest that inexpensive ray theory synthetics may have sufficient accuracy in many similar applications.