Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains
Abstract Temperature records from several randkluft sites at the margins and headwall of Boundary Glacier (lat. 52° 12′ N., long. 117° 12′ W.) in the Canadian Rocky Mountains are presented. These records indicate that during the ablation season a diurnal freeze-thaw air and rock-surface temperature...
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Language: | English |
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Cambridge University Press (CUP)
1987
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Online Access: | http://dx.doi.org/10.1017/s0022143000005359 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005359 |
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crcambridgeupr:10.1017/s0022143000005359 2024-04-28T08:26:47+00:00 Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains Gardner, James S. 1987 http://dx.doi.org/10.1017/s0022143000005359 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005359 en eng Cambridge University Press (CUP) Journal of Glaciology volume 33, issue 113, page 60-67 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1987 crcambridgeupr https://doi.org/10.1017/s0022143000005359 2024-04-09T06:56:17Z Abstract Temperature records from several randkluft sites at the margins and headwall of Boundary Glacier (lat. 52° 12′ N., long. 117° 12′ W.) in the Canadian Rocky Mountains are presented. These records indicate that during the ablation season a diurnal freeze-thaw air and rock-surface temperature regime occurs in a 2 m wide zone centred on the randkluft lip. Deeper in the randkluft , stable sub-zero conditions prevail whereas above the randkluft an above-freezing temperature regime prevails. The freeze-thaw temperature regime, observed freezing of melt water and rain water on randkluft rock surfaces, and copious in-situ loose weathering products on the headwall and marginal free faces suggest an active frost-shattering environment. Down-slope migration of the randkluft lip during the ablation season results in a migration of the freeze-thaw zone and thus a seasonal extension of the rock surface area exposed to the favorable weathering environment. Longer-term glacier fluctuations, with attendant thinning and thickening of the ice body, could result in large areas of marginal and headwall rock surfaces being exposed to the randkluft weathering environment over long periods of time. The data and observations from Boundary Glacier support an idea, suggested by Battle (1960), that open and shallow randklufts , rather than closed and deep bergschrunds, are a focus of weathering at glacier margins and thus a potential factor in cirque development. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 33 113 60 67 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Gardner, James S. Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains |
topic_facet |
Earth-Surface Processes |
description |
Abstract Temperature records from several randkluft sites at the margins and headwall of Boundary Glacier (lat. 52° 12′ N., long. 117° 12′ W.) in the Canadian Rocky Mountains are presented. These records indicate that during the ablation season a diurnal freeze-thaw air and rock-surface temperature regime occurs in a 2 m wide zone centred on the randkluft lip. Deeper in the randkluft , stable sub-zero conditions prevail whereas above the randkluft an above-freezing temperature regime prevails. The freeze-thaw temperature regime, observed freezing of melt water and rain water on randkluft rock surfaces, and copious in-situ loose weathering products on the headwall and marginal free faces suggest an active frost-shattering environment. Down-slope migration of the randkluft lip during the ablation season results in a migration of the freeze-thaw zone and thus a seasonal extension of the rock surface area exposed to the favorable weathering environment. Longer-term glacier fluctuations, with attendant thinning and thickening of the ice body, could result in large areas of marginal and headwall rock surfaces being exposed to the randkluft weathering environment over long periods of time. The data and observations from Boundary Glacier support an idea, suggested by Battle (1960), that open and shallow randklufts , rather than closed and deep bergschrunds, are a focus of weathering at glacier margins and thus a potential factor in cirque development. |
format |
Article in Journal/Newspaper |
author |
Gardner, James S. |
author_facet |
Gardner, James S. |
author_sort |
Gardner, James S. |
title |
Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains |
title_short |
Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains |
title_full |
Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains |
title_fullStr |
Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains |
title_full_unstemmed |
Evidence for Headwall Weathering Zones, Boundary Glacier, Canadian Rocky Mountains |
title_sort |
evidence for headwall weathering zones, boundary glacier, canadian rocky mountains |
publisher |
Cambridge University Press (CUP) |
publishDate |
1987 |
url |
http://dx.doi.org/10.1017/s0022143000005359 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005359 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 33, issue 113, page 60-67 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000005359 |
container_title |
Journal of Glaciology |
container_volume |
33 |
container_issue |
113 |
container_start_page |
60 |
op_container_end_page |
67 |
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1797586032328179712 |