New sea ice estimates over the last 49ky in the southeast Indian Ocean sector of the Southern Ocean

Although many Quaternary records have allowed the study of major glacial-interglacial change in the Southern Ocean, Holocene records from deep-sea cores are few and far between and are currently limited to the South Atlantic. Low sedimentation rates combined with deep seafloors, and the high-nutrient, low-chlorophyll nature of the Southern Ocean are all in part responsible for the lack of decadal-to-centennial resolution records in the open-ocean environment. Our study is focused on an array of sedimentological, micropalaeontological and geochemical analyses conducted on the first open-ocean, high-resolution core study of Quaternary-Holocene sea-ice variability in the Southeast Indian Ocean; Eltanin piston core 27-23. In this presentation the results of sea ice estimates derived from diatom remains and tied to other physical and geological proxies will reveal the change from a sea-ice covered glacial maximum and deglacial transition through to the modern day. We report evidence of several Holocene ice edge advance episodes out to 59 S, inclusive of the Antarctic Climatic Reversal. The addition of this record to existing, lower-resolution, sea-ice histories from regional cores MD88-787 and SO136-111 and in context to modern oceanographic fronts enables scenarios of regional palaeoceanographic change to be refined.