The polar glaciers of the McMurdo Dry Valleys, Antarctica terminate on dry land yet exhibit terminal morphologies characterized by near-vertical cliffs that are partially maintained by the process of dry calving. Ice flow data collected between 2003 and 2007 on Taylor Glacier are described and illum...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.670.388 http://glaciers.pdx.edu/Thesis/Sniffen/sniffen_thesis_2008.pdf |
| Summary: | The polar glaciers of the McMurdo Dry Valleys, Antarctica terminate on dry land yet exhibit terminal morphologies characterized by near-vertical cliffs that are partially maintained by the process of dry calving. Ice flow data collected between 2003 and 2007 on Taylor Glacier are described and illuminate some of the processes that contribute to the development of the near-vertical ice cliffs. Surface velocities are higher in the interior of the glacier (5.0 ± 0.14 ma-1) and lower along the sides (3.0 ± 0.14 ma-1). At surface sites located within 20 meters of the cliff, velocity in the cliff-parallel direction increases with distance from the cliff while cliff-perpendicular velocities do not change appreciably. This motion is consistent with a strain regime of simple shear. Mapping of ice structures at the near-cliff sites document fractures oblique to the cliff edge that are consistent with shearing. Strain rates on the order of 10-3 a-1 also indicate shear but uncertainty is also 10-3 a-1. The velocity profile of ice cliff face may contribute to an overhanging cliff profile. Ablation on the cliff face may contribute to undercutting more than ice flow. |
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