posted on 2015-06-12, 11:02authored byStephen J. Livingstone, R. Storrar, John HillierJohn Hillier, C.R. Stokes, C.D. Clark, L. Tarasov
Eskers record a time-integrated signature of channelised meltwater drainage during
deglaciation providing vital information on the nature and evolution of subglacial drainage. In this
paper, we compare the spatial pattern of eskers beneath the former Laurentide Ice Sheet with
subglacial drainage routes diagnosed at discrete time intervals from the results of a numerical icesheet
model. Perhaps surprisingly, we show that eskers predominantly occur in regions where
modelled subglacial water flow is low. Eskers and modelled subglacial drainage routes were found to
typically match for lengths <10 km, and most eskers show a better agreement with the routes close to
the ice margin just prior to deglaciation. This supports a time-transgressive esker pattern, with
formation in short (<10 km) segments of conduit close behind a retreating ice margin, and probably
associated with thin, stagnant or sluggish ice. Esker forming conduits were probably dominated by
supraglacially fed meltwater inputs. We also show that modelled subglacial drainage routes containing
the largest concentrations of meltwater show a close correlation with palaeo-ice stream locations. The
paucity of eskers along the terrestrial portion of these palaeo-ice streams and meltwater routes is
probably due to the prevalence of distributed drainage and the high erosion potential of fast-flowing
ice.
History
School
Social Sciences
Department
Geography and Environment
Published in
Geomorphology
Citation
LIVINGSTONE, S.J. ... et al, 2015. An ice-sheet scale comparison of eskers with modelled subglacial drainage routes. Geomorphology, 246, pp.104-112.
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This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2015
Notes
This paper was accepted for publication in the journal Geomorphology and the definitive published version is available at http://dx.doi.org/10.1016/j.geomorph.2015.06.016