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Influence of ice-sheet geometry and supraglacial lakes on seasonal ice-flow variability

Lookup NU author(s): Professor Matt King

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Abstract

Supraglacial lakes play an important role in establishing hydrological connections that allow lubricating seasonal meltwater to reach the base of the Greenland Ice Sheet. Here we use new surface velocity observations to examine the influence of supraglacial lake drainages and surface melt rate on ice flow. We find large, spatially extensive speedups concurrent with times of lake drainage, showing that lakes play a key role in modulating regional ice flow. While surface meltwater is supplied to the bed via a geographically sparse network of moulins, the observed ice-flow enhancement suggests that this meltwater spreads widely over the ice-sheet bed. We also find that the complex spatial pattern of speedup is strongly determined by the combined influence of bed and surface topography on subglacial water flow. Thus, modeling of ice-sheet basal hydrology likely will require knowledge of bed topography resolved at scales (sub-kilometer) far finer than existing data (several km).


Publication metadata

Author(s): Joughin I, Das SB, Flowers GE, Behn MD, Alley RB, King MA, Smith BE, Bamber JL, van den Broeke MR, van Angelen JH

Publication type: Article

Publication status: Published

Journal: Cryosphere

Year: 2013

Volume: 7

Issue: 4

Pages: 1185-1192

Print publication date: 26/07/2013

Date deposited: 25/02/2014

ISSN (print): 1994-0416

ISSN (electronic): 1994-0424

Publisher: Copernicus GmbH

URL: http://dx.doi.org/10.5194/tc-7-1185-2013

DOI: 10.5194/tc-7-1185-2013


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Funding

Funder referenceFunder name
NERC
Canada Research Chairs Program (CRC)
Natural Sciences and Engineering Research Council of Canada (NSERC)
ARC-0520382National Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program
ARC-0520382National Science Foundation's Office of Polar Programs (NSF-OPP)
ARC-1023364National Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program
ARC-1023364National Science Foundation's Office of Polar Programs (NSF-OPP)
ANT-0424589NSF
ARC-0520077National Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program
ARC-0520077National Science Foundation's Office of Polar Programs (NSF-OPP)
ARC-0909335NSF
ARC-1023382National Science Foundation's Office of Polar Programs (NSF-OPP)
ARC-1023382National Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program
FT110100207Australian Research Council Future Fellowship
NNX10AI30GNational Science Foundation's Office of Polar Programs (NSF-OPP)
NNX10AI30GNational Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program
NNX10AI33GNational Aeronautics and Space Administration's (NASA) Cryospheric Sciences Program
NNX10AI33GNational Science Foundation's Office of Polar Programs (NSF-OPP)

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