Oscillatory subglacial drainage in the absence of surface melt
The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier i...
Published in: | The Cryosphere |
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2014
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00019955 2023-05-15T16:22:27+02:00 Oscillatory subglacial drainage in the absence of surface melt Schoof, C. Rada, C. A Wilson, N. J. Flowers, G. E. Haseloff, M. 2014-05 electronic https://doi.org/10.5194/tc-8-959-2014 https://noa.gwlb.de/receive/cop_mods_00019955 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019910/tc-8-959-2014.pdf https://tc.copernicus.org/articles/8/959/2014/tc-8-959-2014.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-8-959-2014 https://noa.gwlb.de/receive/cop_mods_00019955 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019910/tc-8-959-2014.pdf https://tc.copernicus.org/articles/8/959/2014/tc-8-959-2014.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2014 ftnonlinearchiv https://doi.org/10.5194/tc-8-959-2014 2022-02-08T22:52:23Z The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier in the St Elias Mountains, Yukon Territory, Canada. Our data indicate the onset of strongly correlated multi-day oscillations in water pressure in multiple boreholes straddling a main drainage axis, starting several weeks after the disappearance of a dominant diurnal mode in August 2011 and persisting until at least January 2012, when multiple data loggers suffered power failure. Jökulhlaups provide a template for understanding spontaneous water pressure oscillations not driven by external supply variability. Using a subglacial drainage model, we show that water pressure oscillations can also be driven on a much smaller scale by the interaction between conduit growth and distributed water storage in smaller water pockets, basal crevasses and moulins, and that oscillations can be triggered when water supply drops below a critical value. We suggest this in combination with a steady background supply of water from ground water or englacial drainage as a possible explanation for the observed wintertime pressure oscillations. Article in Journal/Newspaper glacier* The Cryosphere Yukon Niedersächsisches Online-Archiv NOA Canada Yukon The Cryosphere 8 3 959 976 |
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Niedersächsisches Online-Archiv NOA |
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English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Schoof, C. Rada, C. A Wilson, N. J. Flowers, G. E. Haseloff, M. Oscillatory subglacial drainage in the absence of surface melt |
topic_facet |
article Verlagsveröffentlichung |
description |
The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier in the St Elias Mountains, Yukon Territory, Canada. Our data indicate the onset of strongly correlated multi-day oscillations in water pressure in multiple boreholes straddling a main drainage axis, starting several weeks after the disappearance of a dominant diurnal mode in August 2011 and persisting until at least January 2012, when multiple data loggers suffered power failure. Jökulhlaups provide a template for understanding spontaneous water pressure oscillations not driven by external supply variability. Using a subglacial drainage model, we show that water pressure oscillations can also be driven on a much smaller scale by the interaction between conduit growth and distributed water storage in smaller water pockets, basal crevasses and moulins, and that oscillations can be triggered when water supply drops below a critical value. We suggest this in combination with a steady background supply of water from ground water or englacial drainage as a possible explanation for the observed wintertime pressure oscillations. |
format |
Article in Journal/Newspaper |
author |
Schoof, C. Rada, C. A Wilson, N. J. Flowers, G. E. Haseloff, M. |
author_facet |
Schoof, C. Rada, C. A Wilson, N. J. Flowers, G. E. Haseloff, M. |
author_sort |
Schoof, C. |
title |
Oscillatory subglacial drainage in the absence of surface melt |
title_short |
Oscillatory subglacial drainage in the absence of surface melt |
title_full |
Oscillatory subglacial drainage in the absence of surface melt |
title_fullStr |
Oscillatory subglacial drainage in the absence of surface melt |
title_full_unstemmed |
Oscillatory subglacial drainage in the absence of surface melt |
title_sort |
oscillatory subglacial drainage in the absence of surface melt |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/tc-8-959-2014 https://noa.gwlb.de/receive/cop_mods_00019955 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019910/tc-8-959-2014.pdf https://tc.copernicus.org/articles/8/959/2014/tc-8-959-2014.pdf |
geographic |
Canada Yukon |
geographic_facet |
Canada Yukon |
genre |
glacier* The Cryosphere Yukon |
genre_facet |
glacier* The Cryosphere Yukon |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-8-959-2014 https://noa.gwlb.de/receive/cop_mods_00019955 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019910/tc-8-959-2014.pdf https://tc.copernicus.org/articles/8/959/2014/tc-8-959-2014.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-8-959-2014 |
container_title |
The Cryosphere |
container_volume |
8 |
container_issue |
3 |
container_start_page |
959 |
op_container_end_page |
976 |
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1766010429327278080 |