Basal conditions and ice dynamics inferred from radar-derived internal stratigraphy of the northeast Greenland ice stream
| Autor: | B. A. Keisling, Atsuhiro Muto, J. E. Christian, K. L. Riverman, Knut Christianson, Richard B. Alley, L. E. Peters, Sridhar Anandakrishnan, Robert W. Jacobel |
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| Rok vydání: | 2014 |
| Předmět: |
010506 paleontology
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Ice stream Antarctic sea ice 01 natural sciences Arctic ice pack Ice shelf Fast ice Sea ice Ice divide Ice sheet Geomorphology Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Annals of Glaciology. 55:127-137 |
| ISSN: | 1727-5644 0260-3055 |
| DOI: | 10.3189/2014aog67a090 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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