Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica
Surface debris covers much of the western portion of the McMurdo Ice Shelf and has a strong influence on the local surface albedo and energy balance. Differential ablation between debris-covered and debris-free areas creates an unusual heterogeneous surface of topographically low, high-ablation, and...
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Cambridge University Press
2019
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ftdoajarticles:oai:doaj.org/article:422ac0aaf57d4eb5ad4be4c49eddac59 2023-05-15T14:13:30+02:00 Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica GRANT J. MACDONALD ALISON F. BANWELL IAN C. WILLIS DAVID P. MAYER BECKY GOODSELL DOUGLAS R. MacAYEAL 2019-04-01T00:00:00Z https://doi.org/10.1017/jog.2019.17 https://doaj.org/article/422ac0aaf57d4eb5ad4be4c49eddac59 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143019000170/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2019.17 0022-1430 1727-5652 https://doaj.org/article/422ac0aaf57d4eb5ad4be4c49eddac59 Journal of Glaciology, Vol 65, Pp 337-343 (2019) Glacier hydrology Ice shelves Supraglacial debris Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2019 ftdoajarticles https://doi.org/10.1017/jog.2019.17 2023-03-12T01:30:57Z Surface debris covers much of the western portion of the McMurdo Ice Shelf and has a strong influence on the local surface albedo and energy balance. Differential ablation between debris-covered and debris-free areas creates an unusual heterogeneous surface of topographically low, high-ablation, and topographically raised (‘pedestalled’), low-ablation areas. Analysis of Landsat and MODIS satellite imagery from 1999 to 2018, alongside field observations from the 2016/2017 austral summer, shows that pedestalled relict lakes (‘pedestals’) form when an active surface meltwater lake that develops in the summer, freezes-over in winter, resulting in the lake-bottom debris being masked by a high-albedo, superimposed, ice surface. If this ice surface fails to melt during a subsequent melt season, it experiences reduced surface ablation relative to the surrounding debris-covered areas of the ice shelf. We propose that this differential ablation, and resultant hydrostatic and flexural readjustments of the ice shelf, causes the former supraglacial lake surface to become increasingly pedestalled above the lower topography of the surrounding ice shelf. Consequently, meltwater streams cannot flow onto these pedestalled features, and instead divert around them. We suggest that the development of pedestals has a significant influence on the surface-energy balance, hydrology and flexure of the ice shelf. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ice Shelves Journal of Glaciology McMurdo Ice Shelf Directory of Open Access Journals: DOAJ Articles Austral McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) Journal of Glaciology 65 250 337 343 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Glacier hydrology Ice shelves Supraglacial debris Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Glacier hydrology Ice shelves Supraglacial debris Environmental sciences GE1-350 Meteorology. Climatology QC851-999 GRANT J. MACDONALD ALISON F. BANWELL IAN C. WILLIS DAVID P. MAYER BECKY GOODSELL DOUGLAS R. MacAYEAL Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
topic_facet |
Glacier hydrology Ice shelves Supraglacial debris Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Surface debris covers much of the western portion of the McMurdo Ice Shelf and has a strong influence on the local surface albedo and energy balance. Differential ablation between debris-covered and debris-free areas creates an unusual heterogeneous surface of topographically low, high-ablation, and topographically raised (‘pedestalled’), low-ablation areas. Analysis of Landsat and MODIS satellite imagery from 1999 to 2018, alongside field observations from the 2016/2017 austral summer, shows that pedestalled relict lakes (‘pedestals’) form when an active surface meltwater lake that develops in the summer, freezes-over in winter, resulting in the lake-bottom debris being masked by a high-albedo, superimposed, ice surface. If this ice surface fails to melt during a subsequent melt season, it experiences reduced surface ablation relative to the surrounding debris-covered areas of the ice shelf. We propose that this differential ablation, and resultant hydrostatic and flexural readjustments of the ice shelf, causes the former supraglacial lake surface to become increasingly pedestalled above the lower topography of the surrounding ice shelf. Consequently, meltwater streams cannot flow onto these pedestalled features, and instead divert around them. We suggest that the development of pedestals has a significant influence on the surface-energy balance, hydrology and flexure of the ice shelf. |
format |
Article in Journal/Newspaper |
author |
GRANT J. MACDONALD ALISON F. BANWELL IAN C. WILLIS DAVID P. MAYER BECKY GOODSELL DOUGLAS R. MacAYEAL |
author_facet |
GRANT J. MACDONALD ALISON F. BANWELL IAN C. WILLIS DAVID P. MAYER BECKY GOODSELL DOUGLAS R. MacAYEAL |
author_sort |
GRANT J. MACDONALD |
title |
Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
title_short |
Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
title_full |
Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
title_fullStr |
Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
title_full_unstemmed |
Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
title_sort |
formation of pedestalled, relict lakes on the mcmurdo ice shelf, antarctica |
publisher |
Cambridge University Press |
publishDate |
2019 |
url |
https://doi.org/10.1017/jog.2019.17 https://doaj.org/article/422ac0aaf57d4eb5ad4be4c49eddac59 |
long_lat |
ENVELOPE(166.500,166.500,-78.000,-78.000) |
geographic |
Austral McMurdo Ice Shelf |
geographic_facet |
Austral McMurdo Ice Shelf |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves Journal of Glaciology McMurdo Ice Shelf |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves Journal of Glaciology McMurdo Ice Shelf |
op_source |
Journal of Glaciology, Vol 65, Pp 337-343 (2019) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143019000170/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2019.17 0022-1430 1727-5652 https://doaj.org/article/422ac0aaf57d4eb5ad4be4c49eddac59 |
op_doi |
https://doi.org/10.1017/jog.2019.17 |
container_title |
Journal of Glaciology |
container_volume |
65 |
container_issue |
250 |
container_start_page |
337 |
op_container_end_page |
343 |
_version_ |
1766285970530893824 |