Characterization and interpretation of polythermal structure in two subarctic glaciers
I use ice-penetrating radar to probe the thermal structure in two small glaciers in the Saint Elias Range, southwestern Yukon. I develop processing workflows to separate bed and englacial reflections in radar and use these to build maps of both bed topography and englacial scattering. Comparison wit...
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ftsimonfu:oai:summit.sfu.ca:12553 2023-05-15T18:28:20+02:00 Characterization and interpretation of polythermal structure in two subarctic glaciers Wilson, Nathaniel 2012-11-29 http://summit.sfu.ca/item/12553 unknown etd7550 http://summit.sfu.ca/item/12553 Thesis 2012 ftsimonfu 2022-04-07T18:38:16Z I use ice-penetrating radar to probe the thermal structure in two small glaciers in the Saint Elias Range, southwestern Yukon. I develop processing workflows to separate bed and englacial reflections in radar and use these to build maps of both bed topography and englacial scattering. Comparison with borehole data shows that englacial scattering occurs in ice at the freezing point. The pattern in thermal structure suggests that the observed regime is dominated by accumulation zone processes. I develop a numerical model to simulate steady and time-dependent thermal regimes in glaciers. Diagnostic simulations support the hypothesis that meltwater entrapment is a critical control on the observed structure. Sensitivity tests suggest a climate sensitivity such that thinning and retreat of the near-surface aquifer may dramatically alter the thermal structure. Prognostic simulations illustrate scenarios in which these polythermal glaciers may cool as climate warms in the future. Thesis Subarctic Yukon Summit - SFU Research Repository (Simon Fraser University) Yukon |
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Open Polar |
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Summit - SFU Research Repository (Simon Fraser University) |
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ftsimonfu |
language |
unknown |
description |
I use ice-penetrating radar to probe the thermal structure in two small glaciers in the Saint Elias Range, southwestern Yukon. I develop processing workflows to separate bed and englacial reflections in radar and use these to build maps of both bed topography and englacial scattering. Comparison with borehole data shows that englacial scattering occurs in ice at the freezing point. The pattern in thermal structure suggests that the observed regime is dominated by accumulation zone processes. I develop a numerical model to simulate steady and time-dependent thermal regimes in glaciers. Diagnostic simulations support the hypothesis that meltwater entrapment is a critical control on the observed structure. Sensitivity tests suggest a climate sensitivity such that thinning and retreat of the near-surface aquifer may dramatically alter the thermal structure. Prognostic simulations illustrate scenarios in which these polythermal glaciers may cool as climate warms in the future. |
format |
Thesis |
author |
Wilson, Nathaniel |
spellingShingle |
Wilson, Nathaniel Characterization and interpretation of polythermal structure in two subarctic glaciers |
author_facet |
Wilson, Nathaniel |
author_sort |
Wilson, Nathaniel |
title |
Characterization and interpretation of polythermal structure in two subarctic glaciers |
title_short |
Characterization and interpretation of polythermal structure in two subarctic glaciers |
title_full |
Characterization and interpretation of polythermal structure in two subarctic glaciers |
title_fullStr |
Characterization and interpretation of polythermal structure in two subarctic glaciers |
title_full_unstemmed |
Characterization and interpretation of polythermal structure in two subarctic glaciers |
title_sort |
characterization and interpretation of polythermal structure in two subarctic glaciers |
publishDate |
2012 |
url |
http://summit.sfu.ca/item/12553 |
geographic |
Yukon |
geographic_facet |
Yukon |
genre |
Subarctic Yukon |
genre_facet |
Subarctic Yukon |
op_relation |
etd7550 http://summit.sfu.ca/item/12553 |
_version_ |
1766210778260570112 |