Reconciling marine and terrestrial evidence for post LGM ice

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TitleReconciling marine and terrestrial evidence for post LGM ice sheet retreat in southern McMurdo Sound, AntarcticaAbstractRetreat of the Antarctic ice sheets since the Last Glacial Maximum (LGM) contributed to sea-level rise, but the location, amount, and timing of ice mass loss has been controversial. This paper presents new 10Be exposure ages from glacially transported erratics which record post LGM retreat of grounded ice in the western Ross Sea. Ice elevation in southern McMurdo Sound was â‰¥520 m above present day sea level on the eastern side of Mount Discovery during the LGM, and the onset of major deglaciation in the region was after 14 ka. The ice surface lowered from âˆ¼520 to 234 m above present day sea level between 14.0 ka and 10.3 ka and from 234 m to âˆ¼30 m between 10.3 ka and 7.4 ka. This late-glacial and Holocene deglaciation chronology from southern McMurdo Sound is consistent with other records on the margins of the Ross Embayment, and implies that the western margins of the Ross Sea Ice Sheet (RSIS) experienced most mass loss during the early to middle Holocene. These 10Be exposure ages coupled with sediment provenance define a two-stage ice flow scenario for McMurdo Sound subdividing differing reconstructions into an early and late phase. Prior to Termination I, an expanded Koettlitz Glacier flowed north and northeast between Brown Peninsula and Mount Discovery and coalesced with northward flowing ice fed from the Skelton and Mulock Glaciers. Thinning and retreat of the Koettlitz Glacier and perhaps other outlet glaciers flowing through the Royal Society Range allowed ice grounded in the Ross Sea to flow westward and northward, north of Brown Peninsula. Grounding-line recession in the Ross Sea during the late-glacial and Holocene was likely driven by Southern Ocean warming and sea-level rise from the retreat of the Northern Hemisphere ice sheets and the outer margins of the Antarctic ice sheets. Copyright 2016 Elsevier LtdAcknowledgementsWe thank the anonymous reviewer for their valuable review. This work was supported by New Zealand Ministry for Business, Innovation and Employment contract C05X1001, Australian Institute of Nuclear Science and Engineering Grant 09015, Australian Institute of Nuclear Science and Engineering Postgraduate Research Award 10925 and GNS Science core research funding provided by the Government of New Zealand. We thank Antarctica New Zealand and Southern Lakes Helicopters for transportation and logistical support. Charles Mifsud, Toshiyuki Fujioka and others at ANSTO are thanked for their assistance with sample preparation and AMS analysis.Funding Details09015, AINSE, Australian Institute of Nuclear Science and Engineering; 10925, AINSE, Australian Institute of Nuclear Science and Engineering

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1st AuthorAnderson, J.AuthorAnderson, J.Wilson, G.Fink, D.Lilly, K.Levy, R.Townsend, D.Year2017JournalQuaternary Science ReviewsVolume157Pages1/13/17DOI10.1016/j.quascirev.2016.12.007URLhttps://www.scopus.com/inward/recor.....a5464f5f591b6f9d719395debKeywordsrank5

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TypeArticleCitationAnderson, J., Wilson, G., Fink, D., Lilly, K., Levy, R. and Townsend, D. (2017). Reconciling marine and terrestrial evidence for post LGM ice sheet retreat in southern McMurdo Sound, Antarctica. Quaternary Science Reviews, 157: 1-13 IdentifierAnderson2017Relevancerank5Antarctica NZ supported?YesNZARI?No

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Wilson, G.