Characterising the deglacial history of the East Antarctic ice sheet in central Wilkes Land using marine sediment cores

• Main Author: Tooze, SC
• Format: Thesis
• Language: English
• Published: 2022
• Subjects: East Antarctic Ice Sheet; marine sediment; Wilkes Land; Southern Ocean; sediment provenance; paleoceanography; paleoclimate; Antarctic; East Antarctica; Totten Glacier; Sabrina Coast; Antarc*; Antarctica; Ice Sheet; Sea ice
• Online Access: https://eprints.utas.edu.au/47561/; https://eprints.utas.edu.au/47561/1/Tooze_whole_thesis.pdf

The East Antarctic Ice Sheet (EAIS) retains the largest volume of ice on the planet and has the capacity to raise global sea level by a substantial 52 m. Marine-based sectors of the EAIS are particularly susceptible to retreat and collapse and are currently losing mass at an unprecedented rate. Masked by kilometres of ice and shielded by extensive sea-ice proximal to the coast, central Wilkes Land (between 105-128°E) is one of the most poorly investigated regions of the EAIS. The Totten Glacier, situated in a trench at the Sabrina Coast of central Wilkes Land, drains the largest portion of the EAIS and has one of the highest thinning rates in East Antarctica. Complete melting of the ice drained by the Totten Glacier alone is anticipated to contribute 3.5 m to global sea-level rise. With large portions of the ice sheet in central Wilkes Land grounded below sea-level, on a retrograde slope steepening inland from the coast to the interior basins, this part of the EAIS is sensitive to ocean-forced retreat and marine ice sheet instability, rendering it an important region in the context of global climate change. Understanding the response of the ice sheet to past climate variation is integral for forecasting its future behaviour and for identifying those parts of the ice sheet that are most vulnerable to collapse and retreat in a warming climate. Two high priority objectives in Antarctic paleoclimate research are to determine the principal drivers of ice sheet retreat and to establish the timing of regional deglaciation over the Last Glacial Period-Holocene transition (from c. 25 ka). Thus far, the factors driving ice sheet retreat at the coast of central Wilkes Land over the Last Glacial Period- Holocene transition are not well understood and the timing of the last deglaciation is poorly constrained. The lack of physical samples and the absence of detailed paleoclimate and sediment provenance records from central Wilkes Land provides strong motivation for the research conducted in this thesis. The principal aims of ...