Drivers of abrupt Holocene shifts in West Antarctic ice stre

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TitleDrivers of abrupt Holocene shifts in West Antarctic ice stream direction determined from combined ice sheet modelling and geologic signaturesAbstractDetermining the millennial-scale behaviour of marine-based sectors of the West Antarctic Ice Sheet (WAIS) is critical to improve predictions of the future contribution of Antarctica to sea level rise. Here high-resolution ice sheet modelling was combined with new terrestrial geological constraints (in situ 14C and 10Be analysis) to reconstruct the evolution of two major ice streams entering the Weddell Sea over 20 000 years. The results demonstrate how marked differences in ice flux at the marine margin of the expanded Antarctic ice sheet led to a major reorganization of ice streams in the Weddell Sea during the last deglaciation, resulting in the eastward migration of the Institute Ice Stream, triggering a significant regional change in ice sheet mass balance during the early to mid Holocene. The findings highlight how spatial variability in ice flow can cause marked changes in the pattern, flux and flow direction of ice streams on millennial timescales in this marine ice sheet setting. Given that this sector of the WAIS is assumed to be sensitive to ocean-forced instability and may be influenced by predicted twenty-first century ocean warming, our ability to model and predict abrupt and extensive ice stream diversions is key to a realistic assessment of future ice sheet sensitivity. Ã‚Copyright 2014 Antarctic Science Ltd.AcknowledgementsThis research was supported by the Australian Research Council (FL100100195, FT1201000004 and LP120200724), and UK National Environmental Research Council (AFI 05/03). Fieldwork was supported by Antarctic Logistics and Expeditions and the British Antarctic Survey. NRG gratefully acknowledges support from Victoria University of Wellington and GNS Science. CJF wishes to thank Dr Neil Ross for helpful discussions, Prof David Sugden for instigating this work, and Dr Claus-Dieter Hillenbrand and two anonymous reviewers for their helpful comments.Funding DetailsFL100100195, ARC, Australian Research Council; FT1201000004, ARC, Australian Research Council; LP120200724, ARC, Australian Research Council

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1st AuthorFogwill, C.AuthorFogwill, C.Turney, C.Golledge, N.Rood, D.Hippe, K.Wacker, L.Wieler, R.Rainsley, E.Jones, R.Year2014JournalAntarctic ScienceVolume26Number6Pages674-686DOI10.1017/S0954102014000613URLhttps://www.scopus.com/inward/recor.....d33a032c5058e56a9e7e09764KeywordsHoloceneice flowice sheetice streamlast deglaciationmass balancesea level changestability analysiswarming, Antarctic Ice SheetAntarcticaSouthern OceanWeddell SeaWest Antarctic Ice SheetWest Antarctica, rank1Author Keywordscosmogenic isotopesice stream dynamicsin situ 14Cmarine ice sheet instabilityWeddell SeaWest Antarctic Ice Sheet

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TypeArticleCitationFogwill, C., Turney, C., Golledge, N., Rood, D., Hippe, K., Wacker, L., Wieler, R., Rainsley, E. and Jones, R. (2014). Drivers of abrupt Holocene shifts in West Antarctic ice stream direction determined from combined ice sheet modelling and geologic signatures. Antarctic Science, 26(6): 674-686 IdentifierFogwill2014bRelevancerank1