Terrestrial and submarine evidence for the extent and timing

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TitleTerrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islandsAbstractThis paper is the maritime and sub-Antarctic contribution to the Scientific Committee for Antarctic Research (SCAR) Past Antarctic Ice Sheet Dynamics (PAIS) community Antarctic Ice Sheet reconstruction. The overarching aim for all sectors of Antarctica was to reconstruct the Last Glacial Maximum (LGM) ice sheet extent and thickness, and map the subsequent deglaciation in a series of 5000 year time slices. However, our review of the literature found surprisingly few high quality chronological constraints on changing glacier extents on these timescales in the maritime and sub-Antarctic sector. Therefore, in this paper we focus on an assessment of the terrestrial and offshore evidence for the LGM ice extent, establishing minimum ages for the onset of deglaciation, and separating evidence of deglaciation from LGM limits from those associated with later Holocene glacier fluctuations. Evidence included geomorphological descriptions of glacial landscapes, radiocarbon dated basal peat and lake sediment deposits, cosmogenic isotope ages of glacial features and molecular biological data. We propose a classification of the glacial history of the maritime and sub-Antarctic islands based on this assembled evidence. These include: (Type I) islands which accumulated little or no LGM ice; (Type II) islands with a limited LGM ice extent but evidence of extensive earlier continental shelf glaciations; (Type III) seamounts and volcanoes unlikely to have accumulated significant LGM ice cover; (Type IV) islands on shallow shelves with both terrestrial and submarine evidence of LGM (and/or earlier) ice expansion; (Type V) Islands north of the Antarctic Polar Front with terrestrial evidence of LGM ice expansion; and (Type VI) islands with no data. Finally, we review the climatological and geomorphological settings that separate the glaciological history of the islands within this classification scheme. Copyright 2014 The Authors.AcknowledgementsWe thank the field parties carrying out terrestrial glaciological studies in the sub-Antarctic Islands and the crews and scientific shipboard parties participating in marine geophysical surveys, and the logistics organisations for making all of this field work possible. Furthermore, we acknowledge financial support from the Antarctic Climate Evolution (ACE) and its successor Past Antarctic Ice Sheet Dynamics (PAIS) scientific research programmes of the Scientific Committee on Antarctic Research (SCAR) for a workshop held in 2011 in Edinburgh (UK) that kick-started the Antarctic Ice Sheet community reconstruction initiative. AGCG was supported by a Natural Environment Research Council (NERC) New Investigator Award, NE/K000527/1. We are most grateful to our reviewers for their constructive observations.

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1st AuthorHodgson, D.AuthorHodgson, D.Graham, A.Roberts, S.Bentley, M.Cofaigh, C.Verleyen, E.Vyverman, W.Jomelli, V.Favier, V.Brunstein, D.Verfaillie, D.Colhoun, E.Saunders, K.Selkirk, P.Mackintosh, A.Hedding, D.Nel, W.Hall, K.McGlone, M.Van der Putten, N.Dickens, W.Smith, J.Year2014JournalQuaternary Science ReviewsVolume100Pages137-158DOI10.1016/j.quascirev.2013.12.001URLhttps://www.scopus.com/inward/recor.....a1480d8ad2fea10e4be5a56a9KeywordsGlacial geologyGlaciersIsotopesSubmarines, Antarctic ice sheetsClimateDeglaciationsMaritime AntarcticaQuaternarySub-Antarctica, Ice, continental shelfcosmogenic radionuclidedeglaciationglacial historyglacier dynamicsice sheetLast Glacial Maximumpaleoclimateradiocarbon dating, Antarctic Ice SheetAntarcticaSouthern Ocean, rank1Author KeywordsAntarctic ice sheetClimateDeglaciationMaritime Antarctica glaciationQuaternarySub-Antarctica

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TypeArticleCitationHodgson, D., Graham, A., Roberts, S., Bentley, M., Cofaigh, C., Verleyen, E., Vyverman, W., Jomelli, V., Favier, V., Brunstein, D., Verfaillie, D., Colhoun, E., Saunders, K., Selkirk, P., Mackintosh, A., Hedding, D., Nel, W., Hall, K., McGlone, M., Van der Putten, N., Dickens, W. and Smith, J. (2014). Terrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islands. Quaternary Science Reviews, 100: 137-158 IdentifierHodgson2014Relevancerank1