Model S20A

We have inverted for a three-dimensional model of S-wave velocities in the mantle. The new anisotropic model, called S20A, describes independent variations in Vsv and Vsh in the upper mantle, and isotropic variations in the lower mantle.

The method and results are described in The Unique Anisotropy of the Pacific Upper Mantle. The model is expressed in terms of spherical harmonics in the horizontal direction and Chebyshev polynomials in depth.


Here we give the links to the files which contain the model coefficients and a sample program which calculates S-velocity variations at any given point in the mantle.