The deglacial history of NW Alexander Island, Antarctica, fr
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TitleThe deglacial history of NW Alexander Island, Antarctica, from surface exposure datingAbstractRecent changes along the margins of the Antarctic Peninsula, such as the collapse of the Wilkins Ice Shelf, have highlighted the effects of climatic warming on the Antarctic Peninsula Ice Sheet (APIS). However, such changes must be viewed in a long-term (millennial-scale) context if we are to understand their significance for future stability of the Antarctic ice sheets. To address this, we present nine new cosmogenic 10Be exposure ages from sites on NW Alexander Island and Rothschild Island (adjacent to the Wilkins Ice Shelf) that provide constraints on the timing of thinning of the Alexander Island ice cap since the last glacial maximum. All but one of the 10Be ages are in the range 10.2-21.7ka, showing a general trend of progressive ice-sheet thinning since at least 22ka until 10ka. The data also provide a minimum estimate (490m) for ice-cap thickness on NW Alexander Island at the last glacial maximum. Cosmogenic 3He ages from a rare occurrence of mantle xenoliths on Rothschild Island yield variable ages up to 46ka, probably reflecting exhumation by periglacial processes. Copyright 2011 University of Washington.AcknowledgementsWe thank the Captain, Officers and crew of HMS Endurance, and BAS field assistants Mark Gorin and Roger Stilwell for their support during Antarctic fieldwork. BAS technicians Mike Tabecki and Hilary Blagbrough crushed the rock samples, Adrian Fox provided aerial photographs, and Lydia Gibson (University of Cambridge) donated the mantle xenoliths from her PhD project. The work was performed in part under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. This paper is the result of a collaborative study between the British Geological Survey and the British Antarctic Survey as part of the BAS "Polar Science for Planet Earth programme", funded by the Natural Environment Research Council. The work was also supported by an Antarctic Science Ltd Bursary to JSJ. We thank Jim Knox, Alan Gillespie, Adam Lewis and an anonymous reviewer for their constructive comments.
1st AuthorJohnson, J.AuthorJohnson, J.Everest, J.Leat, P.Golledge, N.Rood, D.Stuart, F.Year2012JournalQuaternary ResearchVolume77Number2Pages273-280DOI10.1016/j.yqres.2011.11.012URLhttps://www.scopus.com/inward/recor.....54ff9ec0bbbb1fdc22d624d39KeywordsCosmogenic nuclidesErraticsIce sheetLast Glacial MaximumRefugiaWilkins Ice Shelf, Glacial geologyGlaciers, Ice, age determinationclimate changedating methoddeglaciationerraticexhumationglacial historyice capice sheetLast Glacial Maximumperiglacial processradiation exposurerefugiumwarmingxenolith, Alexander IslandAntarctic PeninsulaAntarcticaWest AntarcticaWilkins Ice Shelf, rank1Author KeywordsCosmogenic nuclidesErraticsIce sheetLast glacial maximumRefugiaWilkins Ice Shelf
TypeArticleCitationJohnson, J., Everest, J., Leat, P., Golledge, N., Rood, D. and Stuart, F. (2012). The deglacial history of NW Alexander Island, Antarctica, from surface exposure dating. Quaternary Research, 77(2): 273-280 IdentifierJohnson2012Relevancerank1
Stuart, F., The deglacial history of NW Alexander Island, Antarctica, fr , [Johnson2012]. Antarctica NZ, accessed 12/12/2023, https://adam.antarcticanz.govt.nz/nodes/view/63568, 10.1016/j.yqres.2011.11.012