posted on 2023-05-18, 13:42authored byKeisling, BA, Christianson, K, Alley, RB, Peters, LE, Christian, JEM, Anandakrishnan, S, Riverman, KL, Muto, A, Jacobel, RW
We analyze the internal stratigraphy in radio-echo sounding data of the northeast Greenland ice stream to infer past and present ice dynamics. In the upper reaches of the ice stream, we propose that shear-margin steady-state folds in internal reflecting horizons (IRHs) form due to the influence of ice flow over spatially varying basal lubrication. IRHs are generally lower in the ice stream than outside, likely because of greater basal melting in the ice stream from enhanced geothermal flux and heat of sliding. Strain-rate modeling of IRHs deposited during the Holocene indicates no recent major changes in ice-stream vigor or extent in this region. Downstream of our survey, IRHs are disrupted as the ice flows into a prominent overdeepening. When combined with additional data from other studies, these data suggest that upstream portions of the ice stream are controlled by variations in basal lubrication whereas downstream portions are confined by basal topography.
History
Publication title
Annals of Glaciology
Volume
55
Issue
67
Pagination
127-137
ISSN
0260-3055
Department/School
Institute for Marine and Antarctic Studies
Publisher
Int Glaciol Soc
Place of publication
Lensfield Rd, Cambridge, England, Cb2 1Er
Rights statement
Copyright 2014 International Glaciological Society
Repository Status
Open
Socio-economic Objectives
Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts)