| Abstract: | Investigation of the rift zone and flanks of the South Atlantic midoceanic ridge in the Tristan da Cunha hot spot area revealed that their morphostructure is atypical of slow spreading ridges. Feeding the spreading center with magmatic material, the hot spot changes the morphology of the axial zone and transform faults. It itself forms a relief ensemble that differs from the rift one as well. The continuous migration of the spreading center in the westerly direction stimulates the formation of a spacious volcanic highland, which is responsible for the regional asymmetry of ridge flanks in its extended segments (hundreds kilometers long). |
