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- Permanent Link:
- http://dpanther.fiu.edu/dpService/dpPurlService/purl/FI15062068/00001
Material Information
- Title:
- Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation
- Series Title:
- Nature Magazine
- Creator:
- Weber, M.E.
Clark, P.U.
Kuhn, G.
Timmermann, A.
Sprenk, D.
Gladstone, R.
Zhang, X.
Lohmann, G.
Menviel, L.
Chikamoto, M.O.
- Publisher:
- Macmillan Publishers Limited
- Publication Date:
- 2014
- Language:
- English
Notes
- Abstract:
- 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. ( English )
Record Information
- Source Institution:
- Florida International University
- Rights Management:
- 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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