Physical conditions of fast glacier flow: 3. Seasonally-evolving ice deformation on Store Glacier, West Greenland ...
Temporal variations in ice sheet flow directly impact the internal structure within ice sheets through englacial deformation. Large-scale changes in the vertical stratigraphy within ice sheets have been previously conducted on centennial to millennial timescales; however, intra-annual changes in the...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley-Blackwell
2019
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.17863/cam.36083 https://www.repository.cam.ac.uk/handle/1810/288820 |
| Summary: | Temporal variations in ice sheet flow directly impact the internal structure within ice sheets through englacial deformation. Large-scale changes in the vertical stratigraphy within ice sheets have been previously conducted on centennial to millennial timescales; however, intra-annual changes in the morphology of internal layers have yet to be explored. Over a period of two years, we use autonomous phase-sensitive radio-echo sounding (ApRES) to track the daily displacement of internal layers on Store Glacier, West Greenland to millimeter accuracy. At a site located ~30 km from the calving terminus, where the ice is ~600m thick and flows at ~700m/yr, we measure distinct seasonal variations in vertical velocities and vertical strain rates over a two-year period. Prior to the melt season (March–June), we observe increasingly non-linear englacial deformation with negative vertical strain rates (i.e. strain thinning) in the upper half of the ice column of ~0.03 a-1, whereas the ice below thickens under vertical ... |
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