9730964 Crawford Seafloor compliance inversion is one of a very few techniques for determining the melt distribution at oceanic spreading centers. Existing measurements provide evidence for melt in the lower crust and upper mantle beneath the East Pacific Rise at 9 degrees north. Existing computational algorithms designed to calculate compliance over laterally varying basement will be improved and tested, and two- and three-dimensional data inversion routines for complicance data will be developed.