Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica
<jats:title>ABSTRACT</jats:title><jats:p>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 heter...
Main Authors: | , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press (CUP)
2019
|
Subjects: | |
Online Access: | https://www.repository.cam.ac.uk/handle/1810/290741 https://doi.org/10.17863/CAM.37941 |
id |
ftunivcam:oai:www.repository.cam.ac.uk:1810/290741 |
---|---|
record_format |
openpolar |
spelling |
ftunivcam:oai:www.repository.cam.ac.uk:1810/290741 2024-01-14T10:01:32+01:00 Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica Macdonald, GJ Banwell, AF Willis, IANC Mayer, DP Goodsell, B Macayeal, DR 2019 application/pdf https://www.repository.cam.ac.uk/handle/1810/290741 https://doi.org/10.17863/CAM.37941 eng eng Cambridge University Press (CUP) http://dx.doi.org/10.1017/jog.2019.17 Journal of Glaciology https://www.repository.cam.ac.uk/handle/1810/290741 doi:10.17863/CAM.37941 Glacier hydrology Ice shelves Supraglacial debris Article 2019 ftunivcam https://doi.org/10.17863/CAM.37941 2023-12-21T23:24:26Z <jats:title>ABSTRACT</jats:title><jats:p>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.</jats:p> Ian Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf Apollo - University of Cambridge Repository Austral McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Glacier hydrology Ice shelves Supraglacial debris |
spellingShingle |
Glacier hydrology Ice shelves Supraglacial debris Macdonald, GJ Banwell, AF Willis, IANC Mayer, DP Goodsell, B Macayeal, DR Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica |
topic_facet |
Glacier hydrology Ice shelves Supraglacial debris |
description |
<jats:title>ABSTRACT</jats:title><jats:p>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.</jats:p> Ian |
format |
Article in Journal/Newspaper |
author |
Macdonald, GJ Banwell, AF Willis, IANC Mayer, DP Goodsell, B Macayeal, DR |
author_facet |
Macdonald, GJ Banwell, AF Willis, IANC Mayer, DP Goodsell, B Macayeal, DR |
author_sort |
Macdonald, GJ |
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 (CUP) |
publishDate |
2019 |
url |
https://www.repository.cam.ac.uk/handle/1810/290741 https://doi.org/10.17863/CAM.37941 |
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 McMurdo Ice Shelf |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/290741 doi:10.17863/CAM.37941 |
op_doi |
https://doi.org/10.17863/CAM.37941 |
_version_ |
1788067295055052800 |