Rapid erosion beneath the Greenland ice sheet

The Pleistocene ice sheets left a clear signature of erosion, but the rate at which ice sheets erode is difficult to determine from either paleolandscapes or observations of contemporary processes. Here we use two years of sediment flux data, derived from meltwaters emerging from an outlet glacier i...

Full description

Saved in:
Bibliographic Details
Published in:Geology (Boulder) 2012-04, Vol.40 (4), p.343-346
Main Authors: Cowton, T, Nienow, P, Bartholomew, I, Sole, A, Mair, D
Format: Article
Language:English
Subjects:
Arctic region
Cenozoic
erosion
erosion rates
Geological time
Geology
glacial geology
glacial sedimentation
Glaciers
Greenland
Greenland ice sheet
Ice
ice sheets
Leverett Glacier
meltwater
outlet glaciers
Pleistocene
Quaternary
Quaternary geology
sedimentation
southwestern Greenland
subglacial processes
Temperature
Watersheds
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Pleistocene ice sheets left a clear signature of erosion, but the rate at which ice sheets erode is difficult to determine from either paleolandscapes or observations of contemporary processes. Here we use two years of sediment flux data, derived from meltwaters emerging from an outlet glacier in west Greenland, to calculate an average rate of subglacial erosion across a catchment extending >50 km inland from the ice margin. Erosion in this zone occurs at 4.8±2.6 mm a-1, a rate 1-2 orders of magnitude greater than previous estimates of erosion rate beneath the Greenland Ice Sheet. Our results suggest that where surface meltwaters are able to access the bed, the rate of erosion by ice sheets is in keeping with the rapid erosion observed at temperate alpine glaciers. During deglacial phases, when meltwater was abundant, ice sheet margins should therefore have acted as highly efficient agents of erosion.
ISSN:0091-7613
1943-2682
DOI:10.1130/G32687.1