Anisotropic tomography of P‐wave traveltimes

Abstract

The ray path of a P‐wave is specified in terms of the ray parameter and three Euler angles. the P‐wave traveltime depends only on the ray parameter for a spherically symmetric earth. If we introduce an aspherical perturbation, including general ani‐sotropy, the dependence on Euler angles can be expanded in terms of the rotation matrix for a fixed ray parameter. If the perturbation is isotropic, the expansion coefficients satisfy certain relations which may be used to obtain definite evidence for anisotropy rather than isotropic lateral heterogeneity. Copyright © 1995, Wiley Blackwell. All rights reserved