The secret life of ice sails
We present the first dedicated study into the phenomenon of ice sails. These are clean ice structures that protrude from the surface of a small number of debris-covered glaciers and can grow to heights of over 25 m. We draw together what is known about them from the academic/exploration literature a...
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Language: | English |
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2017
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Online Access: | https://research.manchester.ac.uk/en/publications/f61a2821-8805-43bb-8adf-79aa3d2740d2 https://doi.org/10.1017/jog.2017.72 |
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ftumanchesterpub:oai:pure.atira.dk:publications/f61a2821-8805-43bb-8adf-79aa3d2740d2 2023-11-12T04:19:54+01:00 The secret life of ice sails Evatt, Geoffrey Mayer, Christoph Mallinson, Amy Abrahams, I. David Heil, Matthias Nicholson, Lindsey 2017-12 https://research.manchester.ac.uk/en/publications/f61a2821-8805-43bb-8adf-79aa3d2740d2 https://doi.org/10.1017/jog.2017.72 eng eng info:eu-repo/semantics/openAccess Evatt , G , Mayer , C , Mallinson , A , Abrahams , I D , Heil , M & Nicholson , L 2017 , ' The secret life of ice sails ' , Journal of Glaciology , vol. 63 , no. 242 , pp. 1049-1062 . https://doi.org/10.1017/jog.2017.72 article 2017 ftumanchesterpub https://doi.org/10.1017/jog.2017.72 2023-10-30T09:19:25Z We present the first dedicated study into the phenomenon of ice sails. These are clean ice structures that protrude from the surface of a small number of debris-covered glaciers and can grow to heights of over 25 m. We draw together what is known about them from the academic/exploration literature and then analyse imagery. We show here that ice sails can develop by one of two mechanisms, both of which require clean ice to become surrounded by debris-covered ice, where the debris layer is shallow enough for the ice beneath it to melt faster than the clean ice. Once formed, ice sails can persist for decades, in an apparently steady state, before debris layer thickening eventually causes a reversal in the relative melt rates and the ice sails decay to merge back with the surrounding glacier surface. We support our image-based analysis with a surface energy-balance model and show that it compares well with available observations from Baltoro Glacier in the Karakoram. A sensitivity analysis of the model is performed and confirms the results from our empirical study that ice sails require a relatively high evaporative heat flux and/or a relatively low sensible heat flux in order to exist. Article in Journal/Newspaper Journal of Glaciology The University of Manchester: Research Explorer Journal of Glaciology 63 242 1049 1062 |
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Open Polar |
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The University of Manchester: Research Explorer |
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ftumanchesterpub |
language |
English |
description |
We present the first dedicated study into the phenomenon of ice sails. These are clean ice structures that protrude from the surface of a small number of debris-covered glaciers and can grow to heights of over 25 m. We draw together what is known about them from the academic/exploration literature and then analyse imagery. We show here that ice sails can develop by one of two mechanisms, both of which require clean ice to become surrounded by debris-covered ice, where the debris layer is shallow enough for the ice beneath it to melt faster than the clean ice. Once formed, ice sails can persist for decades, in an apparently steady state, before debris layer thickening eventually causes a reversal in the relative melt rates and the ice sails decay to merge back with the surrounding glacier surface. We support our image-based analysis with a surface energy-balance model and show that it compares well with available observations from Baltoro Glacier in the Karakoram. A sensitivity analysis of the model is performed and confirms the results from our empirical study that ice sails require a relatively high evaporative heat flux and/or a relatively low sensible heat flux in order to exist. |
format |
Article in Journal/Newspaper |
author |
Evatt, Geoffrey Mayer, Christoph Mallinson, Amy Abrahams, I. David Heil, Matthias Nicholson, Lindsey |
spellingShingle |
Evatt, Geoffrey Mayer, Christoph Mallinson, Amy Abrahams, I. David Heil, Matthias Nicholson, Lindsey The secret life of ice sails |
author_facet |
Evatt, Geoffrey Mayer, Christoph Mallinson, Amy Abrahams, I. David Heil, Matthias Nicholson, Lindsey |
author_sort |
Evatt, Geoffrey |
title |
The secret life of ice sails |
title_short |
The secret life of ice sails |
title_full |
The secret life of ice sails |
title_fullStr |
The secret life of ice sails |
title_full_unstemmed |
The secret life of ice sails |
title_sort |
secret life of ice sails |
publishDate |
2017 |
url |
https://research.manchester.ac.uk/en/publications/f61a2821-8805-43bb-8adf-79aa3d2740d2 https://doi.org/10.1017/jog.2017.72 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Evatt , G , Mayer , C , Mallinson , A , Abrahams , I D , Heil , M & Nicholson , L 2017 , ' The secret life of ice sails ' , Journal of Glaciology , vol. 63 , no. 242 , pp. 1049-1062 . https://doi.org/10.1017/jog.2017.72 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1017/jog.2017.72 |
container_title |
Journal of Glaciology |
container_volume |
63 |
container_issue |
242 |
container_start_page |
1049 |
op_container_end_page |
1062 |
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1782336143750070272 |