f Seismic traveltime equations for Azimuthally Anisotropic and Isotropic media

The interpretation of traveltime curves over layered anisotropic media would give more physical insight if analytical (although approximate) formulas for such traveltime curves in terms of the subsurface anisotropy were available. In this paper, we derive the analytical expressions for traveltime-offset curves over multilayered weakly azimuthally anisotropic and isotropic media in terms of the elastic properties of each layer. This method is based upon an approximate skewed hyperbolic moveout formula involving three measurement bulk velocities for each reflector: the average vertical velocity and horizontal and skew moveout velocities. This technique allows for fast traveltime computation and extremely rapid estimation of the interval elastic parameters.