Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland
The Cairngorm Mountain area of Scotland is a classic example of a landscape of selective linear glacial erosion, with sharp contrasts in the intensity of glacial erosion between the deeply incised troughs and valleys and the undulating high plateau. This article examines the Quaternary development o...
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crwiley:10.1111/j.1502-3885.2003.tb01437.x 2024-09-15T18:12:32+00:00 Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland HALL, ADRIAN M. GLASSER, NEIL F. 2003 http://dx.doi.org/10.1111/j.1502-3885.2003.tb01437.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2003.tb01437.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2003.tb01437.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Boreas volume 32, issue 1, page 191-207 ISSN 0300-9483 1502-3885 journal-article 2003 crwiley https://doi.org/10.1111/j.1502-3885.2003.tb01437.x 2024-07-30T04:19:52Z The Cairngorm Mountain area of Scotland is a classic example of a landscape of selective linear glacial erosion, with sharp contrasts in the intensity of glacial erosion between the deeply incised troughs and valleys and the undulating high plateau. This article examines the Quaternary development of Glen Avon, a 200 m deep glacial trough set within the high plateau of the mountains. Evidence concerning the aggregate basal thermal regimes of the topographically controlled ice streams that formerly developed in this area is reconstructed from the geomorphological record, including bedforms indicative of wet‐based, sliding ice and of dry‐based ice frozen to its bed. This mapping indicates that basal sliding was not confined exclusively to the troughs but extended towards valley heads and on to parts of the plateau adjacent to troughs. The extent of basal sliding appears to have been greatest beneath pre‐Late Devensian ice sheets. Basal ice temperatures are modelled under steady‐state conditions for the last ice sheet at c. 18 ka BP. Basal thermal regimes are predicted using a reconstruction of the preglacial relief and for the current topography of the area. Convergent flow of ice through the preglacial valley system appears to have been sufficient to induce basal melting and therefore to initiate valley deepening. This effect is enhanced when the model is run across the present topography. Comparison of results of the geomorphological mapping and the modelling reveals significant differences between the actual and predicted extent of basal sliding outside the main ice stream. The overall conclusion is that many ice streams in mountainous terrain are inherited from the locations of preglacial valleys, which serve to accelerate ice flow and promote frictional heating beneath ice sheets. Article in Journal/Newspaper Ice Sheet Wiley Online Library Boreas 32 1 191 207 |
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English |
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The Cairngorm Mountain area of Scotland is a classic example of a landscape of selective linear glacial erosion, with sharp contrasts in the intensity of glacial erosion between the deeply incised troughs and valleys and the undulating high plateau. This article examines the Quaternary development of Glen Avon, a 200 m deep glacial trough set within the high plateau of the mountains. Evidence concerning the aggregate basal thermal regimes of the topographically controlled ice streams that formerly developed in this area is reconstructed from the geomorphological record, including bedforms indicative of wet‐based, sliding ice and of dry‐based ice frozen to its bed. This mapping indicates that basal sliding was not confined exclusively to the troughs but extended towards valley heads and on to parts of the plateau adjacent to troughs. The extent of basal sliding appears to have been greatest beneath pre‐Late Devensian ice sheets. Basal ice temperatures are modelled under steady‐state conditions for the last ice sheet at c. 18 ka BP. Basal thermal regimes are predicted using a reconstruction of the preglacial relief and for the current topography of the area. Convergent flow of ice through the preglacial valley system appears to have been sufficient to induce basal melting and therefore to initiate valley deepening. This effect is enhanced when the model is run across the present topography. Comparison of results of the geomorphological mapping and the modelling reveals significant differences between the actual and predicted extent of basal sliding outside the main ice stream. The overall conclusion is that many ice streams in mountainous terrain are inherited from the locations of preglacial valleys, which serve to accelerate ice flow and promote frictional heating beneath ice sheets. |
format |
Article in Journal/Newspaper |
author |
HALL, ADRIAN M. GLASSER, NEIL F. |
spellingShingle |
HALL, ADRIAN M. GLASSER, NEIL F. Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland |
author_facet |
HALL, ADRIAN M. GLASSER, NEIL F. |
author_sort |
HALL, ADRIAN M. |
title |
Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland |
title_short |
Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland |
title_full |
Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland |
title_fullStr |
Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland |
title_full_unstemmed |
Reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: Glen Avon, Cairngorm Mountains, Scotland |
title_sort |
reconstructing the basal thermal regime of an ice stream in a landscape of selective linear erosion: glen avon, cairngorm mountains, scotland |
publisher |
Wiley |
publishDate |
2003 |
url |
http://dx.doi.org/10.1111/j.1502-3885.2003.tb01437.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2003.tb01437.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2003.tb01437.x |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Boreas volume 32, issue 1, page 191-207 ISSN 0300-9483 1502-3885 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1502-3885.2003.tb01437.x |
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Boreas |
container_volume |
32 |
container_issue |
1 |
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191 |
op_container_end_page |
207 |
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1810450124790300672 |