Virtual Posters

High resolution studies in a well-dated sediment core from the Sub-Antarctic regime of the Indian sector of Southern Ocean demonstrate that different magnetic proxy parameters are environmentally sensitive during last 61,000 years before present (61kaBP). The marine isotopic stage 1 (MIS1) and early MIS3 were characterized by reduced accumulation of magnetic minerals and dominated by fine grained, low coercivity, ferromagnetic minerals, whereas the MIS2 and MIS4 showed enhanced magnetic concentration, that were dominated by coarse grained ferri-magnetic minerals. Comparison of the magnetic proxy data with records of oxygen isotope (?18O), carbonate content and ice rafted debris (IRD) in the core revealed that the lithogenic input fluctuated in tandem with sea surface warming and calcite productivity at the core site. Periods of enhanced lithogenic input and calcite productivity during the last 61kaBP were synchronous with the millennial-scale Antarctic warming events as defined in the Byrd and EPICA ice cores, indicating a direct Antarctic climate linkage. Equatorward shifting of westerly wind system and associated enhancement in the strength of Antarctic Circumpolar Current (ACC) system during inter-stadials may have enhanced the wind induced erosion leading to enhanced lithogenic input to the core site. Major IRD events at the core site are clearly out-of-phase with the northern hemisphere Heinrich events, suggesting a manifestation of the bipolar seesaw mechanism.