The response of the Totten Glacier to past climate warming using marine sediment

The Totten Glacier is responsible for an average ice-loss of 7 ± 2 Gt/yr from East Antarctica (Li et al. 2016) and upon absolute melting, would contribute to a considerable 3.5m rise in global sea-level (Greenbaum et al. 2015). Marine sediment can be used to expand our understanding of ice dynamics and ocean circulation, which will ultimately facilitate the development of current ice sheet climate models. This study focuses on three marine sediment cores recovered aboard the RV Investigator from the continental slope of the Sabrina Coast. Multiple laboratory techniques have been employed to unravel the response of the ocean and the ice sheet to climate variability over the past glacial cycle. A transition from glacial to warmer conditions of the Holocene is characterised by a prominent peak in biological productivity - implying an ice-free, nutrient-rich photic zone. This transition is supported by trends in the XRF data which illustrate a change from clay-rich glaciogenic sediment (higher K/Ti values) to diatom-rich sandy surface sediments (lower K/Ti values) - and by an increase in the abundance of biogenic barium (Ba/Al) - a proxy of productivity export. Ongoing work will quantify the iceberg-rafted debris flux and measure temporal variations in primary productivity and ocean circulation. The provenance and age of heavy minerals will also be determined to help define the subglacial geology of the Aurora Subglacial Basin.