This is a program to study isostasy, subsurface thermal and crustal structure and morphology at the a superfast segment of the EPR and the transform bounding it. The project is built around a detailed gravity and multibeam bathymetric survey of a 185 km long section of the southern EPR axis anf flank located between 7 40 S and 9 20 S which includes the Wilkes transform. This will be the first detailed examination of the off-axis ridge flank and of a transform on the superfast southern EPR using the modern generation of swath mapping and precision gravimeters. This data will allow the PIs to examine the ridge crest and ridge flank isostasy in three dimensions and to address a number of fundamental problems related to the thermal structure, crustal structure, segmentation and evolution of ridge flank morphology along MORs and transforms.