South of the Kane fracture zone, the Mid-Atlantic ridge is segmented into 20-100-km-long spreading cells in which morphology, seismic and gravity signatures change along and across the ridge-axis. The rift valley can be symmetric or asymmetric, and segment centers experience strong magmatic activity whereas low magma supply results in thinning of the crust at segment tips. Submersible observations collected up to 50 km on both sides of the axis were analysed to discuss the processes responsible for the axial valley shape, its possible relationship with deep rock exposures, and to determine the origin of off-axis structures.