The drainage of glacier and ice sheet surface lakes
Supraglacial lakes play a central role in storing melt water, enhancing surface melt, and ultimately in driving ice flow and ice shelf melt through injecting water into the subglacial environment and facilitating fracturing. Here, we develop a model for the drainage of supraglacial lakes through the...
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ftdatacite:10.48550/arxiv.2110.15495 2023-05-15T16:41:03+02:00 The drainage of glacier and ice sheet surface lakes Schoof, Christian Cook, Sue Kulessa, Bernd Thompson, Sarah 2021 https://dx.doi.org/10.48550/arxiv.2110.15495 https://arxiv.org/abs/2110.15495 unknown arXiv Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Fluid Dynamics physics.flu-dyn Geophysics physics.geo-ph FOS Physical sciences Article CreativeWork article Preprint 2021 ftdatacite https://doi.org/10.48550/arxiv.2110.15495 2022-03-10T14:04:53Z Supraglacial lakes play a central role in storing melt water, enhancing surface melt, and ultimately in driving ice flow and ice shelf melt through injecting water into the subglacial environment and facilitating fracturing. Here, we develop a model for the drainage of supraglacial lakes through the dissipation-driven incision of a surface channel. The model consists of the St Venant equations for flow in the channel, fed by an upstream lake reservoir, coupled with an equation for the evolution of channel elevation due to advection, uplift, and downward melting. After reduction to a `stream power'-type hyperbolic model, we show that lake drainage occurs above a critical rate of water supply to the lake due to the backward migration of a shock that incises the lake seal. The critical water supply rate depends on advection velocity and uplift (or more precisely, drawdown downstream of the lake) as well as model parameters such as channel wall roughness and the parameters defining the relationship between channel cross-section and wetted perimeter. Once lake drainage does occur, it can either continue until the lake is empty, or terminate early, leading to oscillatory cycles of lake filling and draining, with the latter favoured by large lake volumes and relatively small water supply rates. Article in Journal/Newspaper Ice Sheet Ice Shelf DataCite Metadata Store (German National Library of Science and Technology) |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Fluid Dynamics physics.flu-dyn Geophysics physics.geo-ph FOS Physical sciences |
spellingShingle |
Fluid Dynamics physics.flu-dyn Geophysics physics.geo-ph FOS Physical sciences Schoof, Christian Cook, Sue Kulessa, Bernd Thompson, Sarah The drainage of glacier and ice sheet surface lakes |
topic_facet |
Fluid Dynamics physics.flu-dyn Geophysics physics.geo-ph FOS Physical sciences |
description |
Supraglacial lakes play a central role in storing melt water, enhancing surface melt, and ultimately in driving ice flow and ice shelf melt through injecting water into the subglacial environment and facilitating fracturing. Here, we develop a model for the drainage of supraglacial lakes through the dissipation-driven incision of a surface channel. The model consists of the St Venant equations for flow in the channel, fed by an upstream lake reservoir, coupled with an equation for the evolution of channel elevation due to advection, uplift, and downward melting. After reduction to a `stream power'-type hyperbolic model, we show that lake drainage occurs above a critical rate of water supply to the lake due to the backward migration of a shock that incises the lake seal. The critical water supply rate depends on advection velocity and uplift (or more precisely, drawdown downstream of the lake) as well as model parameters such as channel wall roughness and the parameters defining the relationship between channel cross-section and wetted perimeter. Once lake drainage does occur, it can either continue until the lake is empty, or terminate early, leading to oscillatory cycles of lake filling and draining, with the latter favoured by large lake volumes and relatively small water supply rates. |
format |
Article in Journal/Newspaper |
author |
Schoof, Christian Cook, Sue Kulessa, Bernd Thompson, Sarah |
author_facet |
Schoof, Christian Cook, Sue Kulessa, Bernd Thompson, Sarah |
author_sort |
Schoof, Christian |
title |
The drainage of glacier and ice sheet surface lakes |
title_short |
The drainage of glacier and ice sheet surface lakes |
title_full |
The drainage of glacier and ice sheet surface lakes |
title_fullStr |
The drainage of glacier and ice sheet surface lakes |
title_full_unstemmed |
The drainage of glacier and ice sheet surface lakes |
title_sort |
drainage of glacier and ice sheet surface lakes |
publisher |
arXiv |
publishDate |
2021 |
url |
https://dx.doi.org/10.48550/arxiv.2110.15495 https://arxiv.org/abs/2110.15495 |
genre |
Ice Sheet Ice Shelf |
genre_facet |
Ice Sheet Ice Shelf |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.48550/arxiv.2110.15495 |
_version_ |
1766031490865430528 |