TY - JOUR
T1 - Basal conditions and ice dynamics inferred from radar-derived internal stratigraphy of the northeast Greenland ice stream
AU - Keisling, Benjamin A.
AU - Christianson, Knut
AU - Alley, Richard B.
AU - Peters, Leo E.
AU - Christian, John E.M.
AU - Anandakrishnan, Sridhar
AU - Riverman, Kiya L.
AU - Muto, Atsuhiro
AU - Jacobel, Robert W.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/7
Y1 - 2014/7
N2 - 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.
AB - 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.
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U2 - 10.3189/2014AoG67A090
DO - 10.3189/2014AoG67A090
M3 - Article
AN - SCOPUS:84902499780
SN - 0260-3055
VL - 55
SP - 127
EP - 137
JO - Annals of Glaciology
JF - Annals of Glaciology
IS - 67
ER -