Controls on Greenland moulin geometry and evolution from the Moulin Shape model
Nearly all meltwater from glaciers and ice sheets is routed englacially through moulins. Therefore, the geometry and evolution of moulins has the potential to influence subglacial water pressure variations, ice motion, and the runoff hydrograph delivered to the ocean. We develop the Moulin Shape (Mo...
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2022
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Online Access: | https://doi.org/10.5194/tc-16-2421-2022 https://doaj.org/article/664a85f56d704445b223a8348b7d54f7 |
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ftdoajarticles:oai:doaj.org/article:664a85f56d704445b223a8348b7d54f7 2023-05-15T16:29:19+02:00 Controls on Greenland moulin geometry and evolution from the Moulin Shape model L. C. Andrews K. Poinar C. Trunz 2022-06-01T00:00:00Z https://doi.org/10.5194/tc-16-2421-2022 https://doaj.org/article/664a85f56d704445b223a8348b7d54f7 EN eng Copernicus Publications https://tc.copernicus.org/articles/16/2421/2022/tc-16-2421-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-2421-2022 1994-0416 1994-0424 https://doaj.org/article/664a85f56d704445b223a8348b7d54f7 The Cryosphere, Vol 16, Pp 2421-2448 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-2421-2022 2022-12-30T23:05:13Z Nearly all meltwater from glaciers and ice sheets is routed englacially through moulins. Therefore, the geometry and evolution of moulins has the potential to influence subglacial water pressure variations, ice motion, and the runoff hydrograph delivered to the ocean. We develop the Moulin Shape (MouSh) model, a time-evolving model of moulin geometry. MouSh models ice deformation around a moulin using both viscous and elastic rheologies and melting within the moulin through heat dissipation from turbulent water flow, both above and below the water line. We force MouSh with idealized and realistic surface melt inputs. Our results show that, under realistic surface melt inputs, variations in surface melt change the geometry of a moulin by approximately 10 % daily and over 100 % seasonally. These size variations cause observable differences in moulin water storage capacity and moulin water levels compared to a static, cylindrical moulin. Our results suggest that moulins are important storage reservoirs for meltwater, with storage capacity and water levels varying over multiple timescales. Implementing realistic moulin geometry within subglacial hydrologic models may therefore improve the representation of subglacial pressures, especially over seasonal periods or in regions where overburden pressures are high. Article in Journal/Newspaper Greenland The Cryosphere Directory of Open Access Journals: DOAJ Articles Greenland The Cryosphere 16 6 2421 2448 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 L. C. Andrews K. Poinar C. Trunz Controls on Greenland moulin geometry and evolution from the Moulin Shape model |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Nearly all meltwater from glaciers and ice sheets is routed englacially through moulins. Therefore, the geometry and evolution of moulins has the potential to influence subglacial water pressure variations, ice motion, and the runoff hydrograph delivered to the ocean. We develop the Moulin Shape (MouSh) model, a time-evolving model of moulin geometry. MouSh models ice deformation around a moulin using both viscous and elastic rheologies and melting within the moulin through heat dissipation from turbulent water flow, both above and below the water line. We force MouSh with idealized and realistic surface melt inputs. Our results show that, under realistic surface melt inputs, variations in surface melt change the geometry of a moulin by approximately 10 % daily and over 100 % seasonally. These size variations cause observable differences in moulin water storage capacity and moulin water levels compared to a static, cylindrical moulin. Our results suggest that moulins are important storage reservoirs for meltwater, with storage capacity and water levels varying over multiple timescales. Implementing realistic moulin geometry within subglacial hydrologic models may therefore improve the representation of subglacial pressures, especially over seasonal periods or in regions where overburden pressures are high. |
format |
Article in Journal/Newspaper |
author |
L. C. Andrews K. Poinar C. Trunz |
author_facet |
L. C. Andrews K. Poinar C. Trunz |
author_sort |
L. C. Andrews |
title |
Controls on Greenland moulin geometry and evolution from the Moulin Shape model |
title_short |
Controls on Greenland moulin geometry and evolution from the Moulin Shape model |
title_full |
Controls on Greenland moulin geometry and evolution from the Moulin Shape model |
title_fullStr |
Controls on Greenland moulin geometry and evolution from the Moulin Shape model |
title_full_unstemmed |
Controls on Greenland moulin geometry and evolution from the Moulin Shape model |
title_sort |
controls on greenland moulin geometry and evolution from the moulin shape model |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-2421-2022 https://doaj.org/article/664a85f56d704445b223a8348b7d54f7 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland The Cryosphere |
genre_facet |
Greenland The Cryosphere |
op_source |
The Cryosphere, Vol 16, Pp 2421-2448 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/2421/2022/tc-16-2421-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-2421-2022 1994-0416 1994-0424 https://doaj.org/article/664a85f56d704445b223a8348b7d54f7 |
op_doi |
https://doi.org/10.5194/tc-16-2421-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
6 |
container_start_page |
2421 |
op_container_end_page |
2448 |
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1766019014973194240 |