Holocene reconfiguration and readvance of the East Antarctic Ice Sheet

Greenwood, S.L., Simkins, L.M., Halberstadt, A.R.W., Prothro, L.O. & Anderson, J.B.

The western Ross Sea. Multibeam data were compiled from NBP cruises 1994–2015, Oden cruises 2007–201
The western Ross Sea. Multibeam data were compiled from NBP cruises 1994–2015, Oden cruises 2007–2010 and Araon cruises 2013–2015. LGM grounding line from ref. 12. Bathymetry and inset panel image from IBCSO76. TNB = Terra Nova Bay, Dv = David Glacier, DIT = Drygalski Ice Tongue, Mw = Mawson Glacier, Ma = Mackay Glacier, McMS = McMurdo Sound, RI = Ross Island, FI = Franklin Island, CH = Coulman High, T.A.M. = Transantarctic Mountains, EAIS = East Antarctic Ice Sheet, WAIS = West Antarctic Ice Sheet

 

Abstract
How ice sheets respond to changes in their grounding line is important in understanding ice sheet vulnerability to climate and ocean changes. The interplay between regional grounding line change and potentially diverse ice flow behaviour of contributing catchments is relevant to an ice sheet’s stability and resilience to change. At the last glacial maximum, marine-based ice streams in the western Ross Sea were fed by numerous catchments draining the East Antarctic Ice Sheet. Here we present geomorphological and acoustic stratigraphic evidence of ice sheet reorganisation in the South Victoria Land (SVL) sector of the western Ross Sea. The opening of a grounding line embayment unzipped ice sheet sub-sectors, enabled an ice flow direction change and triggered enhanced flow from SVL outlet glaciers. These relatively small catchments behaved independently of regional grounding line retreat, instead driving an ice sheet readvance that delivered a significant volume of ice to the ocean and was sustained for centuries.

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