Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation

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|a Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation |h [electronic resource].

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|a [S.l.] : |b Macmillan Publishers Limited, |c 2014.

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|a Nature Magazine |y English.

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|a Please contact the owning institution for licensing and permissions. It is the user's responsibility to ensure use does not violate any third party rights.

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|a Our understanding of the deglacial evolution of the Antarctic Ice Sheet (AIS) following the Last GlacialMaximum(26,000–19,000 years ago)1 is based largely on a few well-dated but temporally and geographically restricted terrestrial and shallow-marine sequences2–4. This sparseness limits our understanding of thedominant feedbacks between the AIS, Southern Hemisphere climate and global sea level. Marine records of iceberg-rafted debris (IBRD) provide a nearly continuous signal of ice-sheetdynamics andvariability. IBRDrecordsfrom the North Atlantic Ocean have been widely used to reconstruct variability in Northern Hemisphere ice sheets5, but comparable records from the Southern Ocean of the AIS are lacking because of the low resolution and large dating uncertainties in existing sediment cores. Here we present two well-dated, high-resolution IBRD records that capture a spatially integrated signal of AIS variability during the last deglaciation.We document eight events of increased iceberg flux from various parts of the AISbetween 20,000 and9,000 years ago, in marked contrast to previous scenarios which identified the main AIS retreat as occurring after meltwater pulse 1A3,6–8 and continuing into the late Holocene epoch. The highest IBRD flux occurred 14,600 years ago, providing the first direct evidence for anAntarctic contribution to meltwater pulse 1A. Climate model simulations with AIS freshwater forcing identify a positive feedback between poleward transport of CircumpolarDeepWater, subsurface warming andAISmelt, suggesting that small perturbations totheicesheetcanbesubstantially enhanced, providing a possible mechanism for rapid sea-level rise.

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|a Climate Change.

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|a Ice Sheets.

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|a Glaciers.

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|a Antarctica.

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|a Weber, M.E..

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|a Clark, P.U..

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|a Kuhn, G..

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|a Timmermann, A..

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|a Sprenk, D..

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|a Gladstone, R..

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|a Zhang, X..

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|a Lohmann, G..

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|a Menviel, L..

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|a Chikamoto, M.O..

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|t Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation

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|a dpSobek.

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|a Sea Level Rise.

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|a dpSobek |c Sea Level Rise

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|u http://dpanther.fiu.edu/dpService/dpPurlService/purl/FI15062068/00001 |y Click here for full text

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|3 FULL TEXT- Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation |u https://www.nature.com/nature/journal/v510/n7503/full/nature13397.html |y Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation

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|a http://dpanther.fiu.edu/sobek/content/FI/15/06/20/68/00001/FI15062068_thm.jpg

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|a Sea Level Rise