Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway
Abstract Digital elevation models of the surface and bed of Midtdalsbreen, Norway are used to calculate subglacial hydraulic potential and infer drainage system structure for a series of subglacial water pressure assumptions ranging from atmospheric to ice overburden. A distributed degree‐day model...
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crwiley:10.1002/hyp.8431 2024-06-23T07:53:04+00:00 Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway Willis, Ian C. Fitzsimmons, Chris D. Melvold, Kjetil Andreassen, Liss M. Giesen, Rianne H. 2012 http://dx.doi.org/10.1002/hyp.8431 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.8431 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.8431 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Hydrological Processes volume 26, issue 25, page 3810-3829 ISSN 0885-6087 1099-1085 journal-article 2012 crwiley https://doi.org/10.1002/hyp.8431 2024-06-13T04:20:58Z Abstract Digital elevation models of the surface and bed of Midtdalsbreen, Norway are used to calculate subglacial hydraulic potential and infer drainage system structure for a series of subglacial water pressure assumptions ranging from atmospheric to ice overburden. A distributed degree‐day model is used to calculate the spatial distribution of melt on the glacier surface throughout a typical summer, which is accumulated along the various drainage system structures to calculate water fluxes beneath the glacier and exiting the portals for the different water pressure assumptions. In addition, 78 dye‐tracing tests were performed from 33 injection sites and numerous measurements of water discharge were made on the main proglacial streams over several summer melt seasons. Comparison of the calculated drainage system structures and water fluxes with dye tracing results and measured proglacial stream discharges suggests that the temporally and spatially averaged steady‐state water pressures beneath the glacier are ~70% of ice overburden. Analysis of the dye return curves, together with the calculated subglacial water fluxes shows that the main drainage network on the eastern half of the glacier consists of a hydraulically efficient system of broad, low channels (average width/height ratio ≈ 75). The smaller drainage network on the west consists of a hydraulically inefficient distributed system, dominated by channels that are exceptionally broad and very low (average width/height ratio ≈ 350). The even smaller central drainage network also consists of a hydraulically inefficient distributed system, dominated by channels that are very broad and exceptionally low (average width/height ratio ≈ 450). The channels beneath the western and central glacier must be so broad and low that they can essentially be thought of as a linked cavity system. Copyright © 2011 John Wiley & Sons, Ltd. Article in Journal/Newspaper glacier Wiley Online Library Norway Hydrological Processes 26 25 3810 3829 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract Digital elevation models of the surface and bed of Midtdalsbreen, Norway are used to calculate subglacial hydraulic potential and infer drainage system structure for a series of subglacial water pressure assumptions ranging from atmospheric to ice overburden. A distributed degree‐day model is used to calculate the spatial distribution of melt on the glacier surface throughout a typical summer, which is accumulated along the various drainage system structures to calculate water fluxes beneath the glacier and exiting the portals for the different water pressure assumptions. In addition, 78 dye‐tracing tests were performed from 33 injection sites and numerous measurements of water discharge were made on the main proglacial streams over several summer melt seasons. Comparison of the calculated drainage system structures and water fluxes with dye tracing results and measured proglacial stream discharges suggests that the temporally and spatially averaged steady‐state water pressures beneath the glacier are ~70% of ice overburden. Analysis of the dye return curves, together with the calculated subglacial water fluxes shows that the main drainage network on the eastern half of the glacier consists of a hydraulically efficient system of broad, low channels (average width/height ratio ≈ 75). The smaller drainage network on the west consists of a hydraulically inefficient distributed system, dominated by channels that are exceptionally broad and very low (average width/height ratio ≈ 350). The even smaller central drainage network also consists of a hydraulically inefficient distributed system, dominated by channels that are very broad and exceptionally low (average width/height ratio ≈ 450). The channels beneath the western and central glacier must be so broad and low that they can essentially be thought of as a linked cavity system. Copyright © 2011 John Wiley & Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
Willis, Ian C. Fitzsimmons, Chris D. Melvold, Kjetil Andreassen, Liss M. Giesen, Rianne H. |
spellingShingle |
Willis, Ian C. Fitzsimmons, Chris D. Melvold, Kjetil Andreassen, Liss M. Giesen, Rianne H. Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway |
author_facet |
Willis, Ian C. Fitzsimmons, Chris D. Melvold, Kjetil Andreassen, Liss M. Giesen, Rianne H. |
author_sort |
Willis, Ian C. |
title |
Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway |
title_short |
Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway |
title_full |
Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway |
title_fullStr |
Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway |
title_full_unstemmed |
Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway |
title_sort |
structure, morphology and water flux of a subglacial drainage system, midtdalsbreen, norway |
publisher |
Wiley |
publishDate |
2012 |
url |
http://dx.doi.org/10.1002/hyp.8431 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhyp.8431 https://onlinelibrary.wiley.com/doi/pdf/10.1002/hyp.8431 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
glacier |
genre_facet |
glacier |
op_source |
Hydrological Processes volume 26, issue 25, page 3810-3829 ISSN 0885-6087 1099-1085 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/hyp.8431 |
container_title |
Hydrological Processes |
container_volume |
26 |
container_issue |
25 |
container_start_page |
3810 |
op_container_end_page |
3829 |
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1802644540165718016 |