Figure F4. Bouguer gravity anomaly map at the ridge/transform intersection (30° MAR). Contribution of seafloor topography has been removed from the free-air anomaly, assuming a density contrast between seawater and ocean crust of 1700 kg/m3. Trackline data from EW0102 and EW9212 have been added to the compilation presented in Blackman et al. (1998). Anomalously high densities occur within Atlantis Massif. Lower than average density (thicker crust?) characterizes the outside corner region near the Fracture Zone. Broader scale thermal contribution of subaxial upwelling (gravity low in northern portion of rift valley) and plate cooling have not been removed.
Next Section | Table of Contents