Monday, 27 August 2007
1.PS-9
The Scotia Sea: Reconstructing glacial climates from diatom assemblages
Lewis Collins1, Claire Allen1, Jenny Pike2, and Dominic Hodgson1. (1) Geological Science Division, British Antarctic Survey, Maddingly Road, High Cross, Cambridge, CB3 0ET, United Kingdom, (2) Earth, Ocean and Planetary Sciences, Cardiff University, Main building, Park Place, Cardiff, CF10 3YE, United Kingdom
We present the preliminary findings of a high-resolution palaeoceanographic record of climate variability during the last glacial cycle. These results are based on the interpretation of diatom assemblages from a sediment core located immediately south of the Polar Front in the north Scotia Sea. High-frequency fluctuations in diatom concentration and assemblage composition allude to significant variations in oceanographic conditions. Diatom assemblages at the MIS 3 – MIS 2 transition reflect high-frequency variability within the sea-ice/open ocean dynamic. Fluctuating abundances of the sea-ice indicator group F. curta/F. cylindrus indicate the persistent advance and retreat of sea-ice over the core site. Synchronicity of the F. curta/F. cylindrus group trend with that of Chaetocerous resting spores (CRS) is indicative of gradual spring melt back at the sea-ice edge. Reconstructing the fluctuations of the glacial climate of the Scotia Sea will aid in understanding the role the Southern Ocean played during the late Quaternary