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

Citation

Joughin, I and Das, SB and Flowers, GE and Behn, MD and Alley, RB and King, MA and Smith, BE and Bamber, JL and van den Broeke, MR and van Angelen, JH, Influence of ice-sheet geometry and supraglacial lakes on seasonal ice-flow variability, Cryosphere, 7, (4) pp. 1185-1192. ISSN 1994-0416 (2013) [Refereed Article]


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Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/

DOI: doi:10.5194/tc-7-1185-2013

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).

Item Details

Item Type:Refereed Article
Keywords:Greenland, ice sheet, sea level
Research Division:Engineering
Research Group:Geomatic Engineering
Research Field:Geodesy
Objective Division:Environment
Objective Group:Climate and Climate Change
Objective Field:Global Effects of Climate Change and Variability (excl. Australia, New Zealand, Antarctica and the South Pacific) (excl. Social Impacts)
Author:King, MA (Professor Matt King)
ID Code:88542
Year Published:2013
Funding Support:Australian Research Council (FT110100207)
Web of Science® Times Cited:36
Deposited By:Geography and Environmental Studies
Deposited On:2014-02-06
Last Modified:2014-08-05
Downloads:470 View Download Statistics

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