The geometry and flow of Fireweed Rock Glacier, Alaska
Thesis (M.S.) University of Alaska Fairbanks, 2002 Little is known about the geometry, internal structure or flow of rock glaciers. Geophysical investigations were carried out on Fireweed Rock Glacier to define its geometry. Transient electromagnetic (TEM) methods were effective in determining its s...
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| Format: | Thesis |
| Language: | English |
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2002
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| Online Access: | http://hdl.handle.net/11122/6911 |
| Summary: | Thesis (M.S.) University of Alaska Fairbanks, 2002 Little is known about the geometry, internal structure or flow of rock glaciers. Geophysical investigations were carried out on Fireweed Rock Glacier to define its geometry. Transient electromagnetic (TEM) methods were effective in determining its shape and depth as well as re-enforcing results of radar and seismic. All of these methods suggest a discontinuity at 15 to 30 m depth. The geometry acquired from these geophysical surveys was used to investigate the motion of the rock glacier. Analysis indicates that motion is concentrated in a pseudo-rectangular subsection of the larger valley on a 'shear plane' at about 27 m depth. We infer that both deformation above and 'sliding' along this shear plane contribute to the observed surface motion. This rock glacier flows relatively quickly for a rock glacier, and has seasonal and annual variations in speed. Some of the variations are related to the quasi-periodic calving at the terminus. |
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