In recent years, ground-penetrating radar (GPR) has been increasingly used for characteri-zation of subglacial and englacial environments at polythermal glaciers. The geophysical method is able to exploit the dielectric difference between water, air, sediment and ice, allowing delineation of subsurf...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.536.520 http://people.ucalgary.ca/~moorman/ESPL2006.pdf |
| Summary: | In recent years, ground-penetrating radar (GPR) has been increasingly used for characteri-zation of subglacial and englacial environments at polythermal glaciers. The geophysical method is able to exploit the dielectric difference between water, air, sediment and ice, allowing delineation of subsurface hydrological, thermal and structural conditions. More recent GPR research has endeavoured to examine temporal change in glaciers, in particular the distribution of the cold ice zone at polythermal glaciers. However, the exact nature of temporal change that can be identified using GPR has not been fully examined. This re-search presents the results of three GPR surveys conducted over the course of a summer ablation season at a polythermal glacier in the Canadian Arctic. A total of approximately 30 km of GPR profiles were collected in 2002 repeatedly covering the lower 2 km of Stagna-tion Glacier, Bylot Island (72°58 ′ N 78°22 ′ W). Comparison between profiles indicated changes in the radar signature, including increased noise, appearance and disappearance of englacial reflections, and signal attenuation in the latter survey. Further, an area of chaotic returns in up-glacier locations, which was interpreted to be a wet temperate ice zone, showed marked |
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