The satellite altimeters aboard the Geosat and ERS-1 spacecraft have mapped the marine gravity field over nearly all of the world's oceans to a high accuracy. The Geosat data south of 30 degrees south has recently been declassified. In the wavelength band 15 to 150 km, variations in gravity anomaly are highly correlated with seafloor topography. Since many southern ocean areas are sparsely surveyed, these new Geosat data reveal many previously unsurveyed features. The objectives of this project are to: (1) merge the Scripps satellite altimeter processing system with the shipboard data processing system so these data sets can be compared and correlated, (2) investigate three methods for constructing inverse transfer functions for mapping dense satellite gravity onto the sparse ship topography profiles, (3) extract regional variations in the topography/gravity transfer function and relate them to tectonic provinces, (4) use topography/transfer functions to interpolate seafloor topography between sparse ship sounding, and (5) examine variations in topography/gravity transfer function at spreading ridges with emphasis on the variation with spreading rate and distance to ridge/transform intersection.
