The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier
In cold and arid climates, small glaciers with cold accumulation zones are often thought to be entirely cold based. However, scattering in ground-penetrating radar (GPR) measurements on the Rikha Samba Glacier in the Nepal Himalayas suggests a large amount of temperate ice that seems to be influence...
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Copernicus Publications
2020
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Online Access: | https://doi.org/10.5194/tc-14-1273-2020 https://www.the-cryosphere.net/14/1273/2020/tc-14-1273-2020.pdf https://doaj.org/article/50816083aced44f5a8c984da275a3487 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:50816083aced44f5a8c984da275a3487 2023-05-15T18:32:16+02:00 The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier A. Gilbert A. Sinisalo T. R. Gurung K. Fujita S. B. Maharjan T. C. Sherpa T. Fukuda 2020-04-01 https://doi.org/10.5194/tc-14-1273-2020 https://www.the-cryosphere.net/14/1273/2020/tc-14-1273-2020.pdf https://doaj.org/article/50816083aced44f5a8c984da275a3487 en eng Copernicus Publications doi:10.5194/tc-14-1273-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/1273/2020/tc-14-1273-2020.pdf https://doaj.org/article/50816083aced44f5a8c984da275a3487 undefined The Cryosphere, Vol 14, Pp 1273-1288 (2020) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/tc-14-1273-2020 2023-01-22T17:50:17Z In cold and arid climates, small glaciers with cold accumulation zones are often thought to be entirely cold based. However, scattering in ground-penetrating radar (GPR) measurements on the Rikha Samba Glacier in the Nepal Himalayas suggests a large amount of temperate ice that seems to be influenced by the presence of crevassed areas. We used a coupled thermo-mechanical model forced by a firn model accounting for firn heating to interpret the observed thermal regime. Using a simple energy conservation approach, we show that the addition of water percolation and refreezing in crevassed areas explains these observations. Model experiments show that both steady and transient thermal regimes are significantly affected by latent heat release in crevassed areas. This makes half of the glacier base temperate, resulting in an ice dynamic mainly controlled by basal friction instead of ice deformation. The timescale of thermal regime change, in response to atmospheric warming, is also greatly diminished, with a potential switch from cold to temperate basal ice in 50–60 years in the upper part of the glacier instead of the 100–150 years that it would take without the effect of the crevasses. This study highlights the crucial role of water percolation through the crevasses on the thermal regime of glaciers and validates a simple method to account for it in glacier thermo-mechanical models. Article in Journal/Newspaper The Cryosphere Unknown The Cryosphere 14 4 1273 1288 |
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English |
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geo envir A. Gilbert A. Sinisalo T. R. Gurung K. Fujita S. B. Maharjan T. C. Sherpa T. Fukuda The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier |
topic_facet |
geo envir |
description |
In cold and arid climates, small glaciers with cold accumulation zones are often thought to be entirely cold based. However, scattering in ground-penetrating radar (GPR) measurements on the Rikha Samba Glacier in the Nepal Himalayas suggests a large amount of temperate ice that seems to be influenced by the presence of crevassed areas. We used a coupled thermo-mechanical model forced by a firn model accounting for firn heating to interpret the observed thermal regime. Using a simple energy conservation approach, we show that the addition of water percolation and refreezing in crevassed areas explains these observations. Model experiments show that both steady and transient thermal regimes are significantly affected by latent heat release in crevassed areas. This makes half of the glacier base temperate, resulting in an ice dynamic mainly controlled by basal friction instead of ice deformation. The timescale of thermal regime change, in response to atmospheric warming, is also greatly diminished, with a potential switch from cold to temperate basal ice in 50–60 years in the upper part of the glacier instead of the 100–150 years that it would take without the effect of the crevasses. This study highlights the crucial role of water percolation through the crevasses on the thermal regime of glaciers and validates a simple method to account for it in glacier thermo-mechanical models. |
format |
Article in Journal/Newspaper |
author |
A. Gilbert A. Sinisalo T. R. Gurung K. Fujita S. B. Maharjan T. C. Sherpa T. Fukuda |
author_facet |
A. Gilbert A. Sinisalo T. R. Gurung K. Fujita S. B. Maharjan T. C. Sherpa T. Fukuda |
author_sort |
A. Gilbert |
title |
The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier |
title_short |
The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier |
title_full |
The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier |
title_fullStr |
The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier |
title_full_unstemmed |
The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier |
title_sort |
influence of water percolation through crevasses on the thermal regime of a himalayan mountain glacier |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-1273-2020 https://www.the-cryosphere.net/14/1273/2020/tc-14-1273-2020.pdf https://doaj.org/article/50816083aced44f5a8c984da275a3487 |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 14, Pp 1273-1288 (2020) |
op_relation |
doi:10.5194/tc-14-1273-2020 1994-0416 1994-0424 https://www.the-cryosphere.net/14/1273/2020/tc-14-1273-2020.pdf https://doaj.org/article/50816083aced44f5a8c984da275a3487 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-14-1273-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
4 |
container_start_page |
1273 |
op_container_end_page |
1288 |
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1766216364055330816 |