COULD DEEP SUB-ANTARCTIC CONVECTION FEED THE WORLD DEEP BASINS DURINGTHE LAST GLACIAL MAXIMUM

Simple box model calculations are used to simulate the oceanic circula tion during the last glacial maximum (LGM). These experiments show tha t the main features of the delta(13)C and Delta(14)C distributions and of the lysocline depth may be explained by a circulation pattern very different from the modern one. Intermediate and upper deep waters wer e produced in the North Atlantic Ocean, whereas deep waters of Subanta rctic Mode type, forming at the northern edge of the Subantarctic conv ergence, invaded the main oceanic basins. The Southern Ocean, mainly s elf ventilated, had a reduced deep component that flew southward along the East Pacific Ridge and the Australian west cost. The thermodynami c fractionation that occurs during air-sea exchange has only contribut ed slightly to the glacial deep delta(13)C distribution through surfac e water temperature variations.