A note on the water budget of temperate glaciers
In this note, the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy due to the downward motion of mass (ice, snow, meltwater and rain). A mathematical formulation of the dissipation is de...
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Copernicus Publications
2013
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Online Access: | https://doi.org/10.5194/tc-7-1557-2013 http://www.the-cryosphere.net/7/1557/2013/tc-7-1557-2013.pdf https://doaj.org/article/d90c699f412d47fea1b6a596d4700bdd |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:d90c699f412d47fea1b6a596d4700bdd 2023-05-15T18:32:21+02:00 A note on the water budget of temperate glaciers J. Oerlemans 2013-09-01 https://doi.org/10.5194/tc-7-1557-2013 http://www.the-cryosphere.net/7/1557/2013/tc-7-1557-2013.pdf https://doaj.org/article/d90c699f412d47fea1b6a596d4700bdd en eng Copernicus Publications doi:10.5194/tc-7-1557-2013 1994-0416 1994-0424 http://www.the-cryosphere.net/7/1557/2013/tc-7-1557-2013.pdf https://doaj.org/article/d90c699f412d47fea1b6a596d4700bdd undefined The Cryosphere, Vol 7, Iss 5, Pp 1557-1564 (2013) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2013 fttriple https://doi.org/10.5194/tc-7-1557-2013 2023-01-22T19:19:09Z In this note, the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy due to the downward motion of mass (ice, snow, meltwater and rain). A mathematical formulation of the dissipation is developed and applied to a simple glacier geometry. In the next step, meltwater production resulting from enhanced ice motion during a glacier surge is calculated. The amount of melt energy available follows directly from the lowering of the centre of gravity of the glacier. To illustrate the concept, schematic calculations are presented for a number of glaciers with different geometric characteristics. Typical dissipative melt rates, expressed as water-layer depth averaged over the glacier, range from a few centimetres per year for smaller glaciers to half a metre per year for Franz Josef Glacier, one of the most active glaciers in the world (in terms of mass turnover). The total generation of meltwater during a surge is typically half a metre. For Variegated Glacier a value of 70 cm is found, for Kongsvegen 20 cm. These values refer to water layer depth averaged over the entire glacier. The melt extit{rate} depends on the duration of the surge. It is generally an order of magnitude greater than water production by `normal' dissipation. On the other hand, the additional basal melt rate during a surge is comparable in magnitude with the water input from meltwater and precipitation. This suggests that enhanced melting during a surge does not grossly change the total water budget of a glacier. Basal water generated by enhanced sliding is an important ingredient in many theories of glacier surges. It provides a positive feedback mechanism that actually makes the surge happen. The results found here suggest that this can only work if water generated by enhanced sliding accumulates in a part of the glacier base where surface meltwater and rain have no or very limited access. This finding seems compatible with the fact that, ... Article in Journal/Newspaper The Cryosphere Unknown Kongsvegen ENVELOPE(12.657,12.657,78.854,78.854) The Cryosphere 7 5 1557 1564 |
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English |
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geo envir J. Oerlemans A note on the water budget of temperate glaciers |
topic_facet |
geo envir |
description |
In this note, the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy due to the downward motion of mass (ice, snow, meltwater and rain). A mathematical formulation of the dissipation is developed and applied to a simple glacier geometry. In the next step, meltwater production resulting from enhanced ice motion during a glacier surge is calculated. The amount of melt energy available follows directly from the lowering of the centre of gravity of the glacier. To illustrate the concept, schematic calculations are presented for a number of glaciers with different geometric characteristics. Typical dissipative melt rates, expressed as water-layer depth averaged over the glacier, range from a few centimetres per year for smaller glaciers to half a metre per year for Franz Josef Glacier, one of the most active glaciers in the world (in terms of mass turnover). The total generation of meltwater during a surge is typically half a metre. For Variegated Glacier a value of 70 cm is found, for Kongsvegen 20 cm. These values refer to water layer depth averaged over the entire glacier. The melt extit{rate} depends on the duration of the surge. It is generally an order of magnitude greater than water production by `normal' dissipation. On the other hand, the additional basal melt rate during a surge is comparable in magnitude with the water input from meltwater and precipitation. This suggests that enhanced melting during a surge does not grossly change the total water budget of a glacier. Basal water generated by enhanced sliding is an important ingredient in many theories of glacier surges. It provides a positive feedback mechanism that actually makes the surge happen. The results found here suggest that this can only work if water generated by enhanced sliding accumulates in a part of the glacier base where surface meltwater and rain have no or very limited access. This finding seems compatible with the fact that, ... |
format |
Article in Journal/Newspaper |
author |
J. Oerlemans |
author_facet |
J. Oerlemans |
author_sort |
J. Oerlemans |
title |
A note on the water budget of temperate glaciers |
title_short |
A note on the water budget of temperate glaciers |
title_full |
A note on the water budget of temperate glaciers |
title_fullStr |
A note on the water budget of temperate glaciers |
title_full_unstemmed |
A note on the water budget of temperate glaciers |
title_sort |
note on the water budget of temperate glaciers |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/tc-7-1557-2013 http://www.the-cryosphere.net/7/1557/2013/tc-7-1557-2013.pdf https://doaj.org/article/d90c699f412d47fea1b6a596d4700bdd |
long_lat |
ENVELOPE(12.657,12.657,78.854,78.854) |
geographic |
Kongsvegen |
geographic_facet |
Kongsvegen |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 7, Iss 5, Pp 1557-1564 (2013) |
op_relation |
doi:10.5194/tc-7-1557-2013 1994-0416 1994-0424 http://www.the-cryosphere.net/7/1557/2013/tc-7-1557-2013.pdf https://doaj.org/article/d90c699f412d47fea1b6a596d4700bdd |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-7-1557-2013 |
container_title |
The Cryosphere |
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7 |
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5 |
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1557 |
op_container_end_page |
1564 |
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1766216450785148928 |