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Short-term variability in Greenland Ice Sheet motion forced by time-varying meltwater drainage: implications for the relationship between subglacial drainage system behavior and ice velocity

Citation

Bartholomew, I and Nienow, P and Sole, A and Mair, D and Cowton, T and King, MA, Short-term variability in Greenland Ice Sheet motion forced by time-varying meltwater drainage: implications for the relationship between subglacial drainage system behavior and ice velocity, Journal of Geophysical Research, 117, (F3) Article F03002. ISSN 0148-0227 (2012) [Refereed Article]

Copyright Statement

Copyright 2012 American Geophysical Union

DOI: doi:10.1029/2011JF002220

Abstract

High resolution measurements of ice motion along a 120 km transect in a land-terminating section of the GrIS reveal short-term velocity variations (<1 day), which are forced by rapid variations in meltwater input to the subglacial drainage system from the ice sheet surface. The seasonal changes in ice velocity at low elevations (<1000 m) are dominated by events lasting from 1 day to 1 week, although daily cycles are largely absent at higher elevations, reflecting different patterns of meltwater input. Using a simple model of subglacial conduit behavior we show that the seasonal record of ice velocity can be understood in terms of a time-varying water input to a channelized subglacial drainage system. Our investigation substantiates arguments that variability in the duration and rate, rather than absolute volume, of meltwater delivery to the subglacial drainage system are important controls on seasonal patterns of subglacial water pressure, and therefore ice velocity. We suggest that interpretations of hydro-dynamic behavior in land-terminating sections of the GrIS margin which rely on steady state drainage theories are unsuitable for making predictions about the effect of increased summer ablation on future rates of ice motion.

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:Climate and Climate Change not elsewhere classified
Author:King, MA (Professor Matt King)
ID Code:89655
Year Published:2012
Web of Science® Times Cited:72
Deposited By:Geography and Environmental Studies
Deposited On:2014-03-11
Last Modified:2017-10-30
Downloads:0

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