Velocity analysis and imaging in transversely isotropic media: Methodology and a case study

Abstract

Physicists and mathematicians, for many years, have studied the intricacies and complexities of how elastic waves propagate in anisotropic media (media in which velocity varies with direction of propagation). Moveover, over the years, a select few visionary exploration geophysicists (e.g., G. Postma, F. Levin, and K. Helbig) have been telling us that the earth’s subsurface is not isotropic, so processing that fails to take anisotropy into account should yield biased estimates of depth and subsurface velocity. Nevertheless, it is only in this past decade that the anisotropic character of the earth’s subsurface has been seriously studied and treated. During that time, most emphasis has been focused on the influence of anisotropy on the behavior of shear waves (e.g. Crampin 1985), a common belief being that departures of medium properties from isotropic waves were of second order for P-waves.