Changes in deep water hydrology during the Last Deglaciation

Changes in benthic foraminifera δ18O and δ13C have been followed over the last deglaciation period in seven sediment cores from different water depths in the North Atlantic, Indian and Pacific Ocean. The two periods of most rapid δ18O changes, at about 17 and 12 ka, are recorded in all intermediate water cores simultaneously with the penetration of brines formed along the polar ice shelves, exhibiting low δ18O and δ13C signatures. At the opposite, exchanges between intermediate and deep waters were slow. But here again, Atlantic and Pacific deep waters were affected simultaneously. These results would give a major role to convection around Antarctica a major role in deep circulation during these periods. To cite this article: L. Labeyrie et al., C. R. Geoscience 337 (2005).