Millennial-scale changes in North Atlantic Deep Water circulation during marine isotope stages 11 and 12: Linkage to Antarctic climate

The time interval represented by marine isotope stages (MIS) 11 and 12 (ca. 360-470 ka) may contain the most extreme glacial and interglacial climate conditions of the late Pleistocene. Sediments from the Bermuda Rise (wester n North Atlantic) provide clues to the nature of climate variability during this period. Our geochemical records indicate that millennial-scale climat e instability and associated changes in North Atlantic Deep Water (NADW) pr oduction occurred during both interglacial MIS 11 and glacial MIS 12, Stage 12 is punctuated by a series of interstadial events that occurred at a 5-6 k.y. periodicity, and the occurrence of ice-rafted debris at various times during stage 12 indicates that icebergs were present at least as far south as 34 degrees N during this glacial period. Within the limits of our corre lation, the atmospheric temperature changes recently reported for the Vosto k ice core for the stage 11 time period appear to be represented by coeval changes in NADW flow. Specifically, warming in Antarctica is associated wit h increased production of NADW.