Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier.
Supraglacial lake drainage events influence Greenland Ice Sheet dynamics on hourly to interannual timescales. However, direct observations are rare, and, to date, no in situ studies exist from fast-flowing sectors of the ice sheet. Here, we present observations of a rapid lake drainage event at Stor...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/299570 2024-02-04T10:00:34+01:00 Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. Chudley, Thomas R Christoffersen, Poul Doyle, Samuel H Bougamont, Marion Schoonman, Charlotte M Hubbard, Bryn James, Mike R 2019-12-17 Print-Electronic application/pdf https://www.repository.cam.ac.uk/handle/1810/299570 https://doi.org/10.17863/CAM.46643 eng eng Proceedings of the National Academy of Sciences http://dx.doi.org/10.1073/pnas.1913685116 Proc Natl Acad Sci U S A https://www.repository.cam.ac.uk/handle/1810/299570 doi:10.17863/CAM.46643 Greenland glaciology hydrology ice sheets lakes Article 2019 ftunivcam https://doi.org/10.17863/CAM.46643 2024-01-11T23:28:30Z Supraglacial lake drainage events influence Greenland Ice Sheet dynamics on hourly to interannual timescales. However, direct observations are rare, and, to date, no in situ studies exist from fast-flowing sectors of the ice sheet. Here, we present observations of a rapid lake drainage event at Store Glacier, west Greenland, in 2018. The drainage event transported 4.8 × 106 m3 of meltwater to the glacier bed in ∼5 h, reducing the lake to a third of its original volume. During drainage, the local ice surface rose by 0.55 m, and surface velocity increased from 2.0 m⋅d-1 to 5.3 m⋅d-1 Dynamic responses were greatest ∼4 km downstream from the lake, which we interpret as an area of transient water storage constrained by basal topography. Drainage initiated, without any precursory trigger, when the lake expanded and reactivated a preexisting fracture that had been responsible for a drainage event 1 y earlier. Since formation, this fracture had advected ∼500 m from the lake's deepest point, meaning the lake did not fully drain. Partial drainage events have previously been assumed to occur slowly via lake overtopping, with a comparatively small dynamic influence. In contrast, our findings show that partial drainage events can be caused by hydrofracture, producing new hydrological connections that continue to concentrate the supply of surface meltwater to the bed of the ice sheet throughout the melt season. Our findings therefore indicate that the quantity and resultant dynamic influence of rapid lake drainages are likely being underestimated. This research was funded by the European Research Council as part of the RESPONDER project under the European Union’s Horizon 2020 research and innovation programme (grant 683043). TRC was supported by a Natural Environment Research Council Doctoral Training Partnership Studentship (grant NE/L002507/1). Article in Journal/Newspaper glacier Greenland greenlandic Ice Sheet Apollo - University of Cambridge Repository Greenland Rapid Lake ENVELOPE(177.619,177.619,52.064,52.064) |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Greenland glaciology hydrology ice sheets lakes |
spellingShingle |
Greenland glaciology hydrology ice sheets lakes Chudley, Thomas R Christoffersen, Poul Doyle, Samuel H Bougamont, Marion Schoonman, Charlotte M Hubbard, Bryn James, Mike R Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. |
topic_facet |
Greenland glaciology hydrology ice sheets lakes |
description |
Supraglacial lake drainage events influence Greenland Ice Sheet dynamics on hourly to interannual timescales. However, direct observations are rare, and, to date, no in situ studies exist from fast-flowing sectors of the ice sheet. Here, we present observations of a rapid lake drainage event at Store Glacier, west Greenland, in 2018. The drainage event transported 4.8 × 106 m3 of meltwater to the glacier bed in ∼5 h, reducing the lake to a third of its original volume. During drainage, the local ice surface rose by 0.55 m, and surface velocity increased from 2.0 m⋅d-1 to 5.3 m⋅d-1 Dynamic responses were greatest ∼4 km downstream from the lake, which we interpret as an area of transient water storage constrained by basal topography. Drainage initiated, without any precursory trigger, when the lake expanded and reactivated a preexisting fracture that had been responsible for a drainage event 1 y earlier. Since formation, this fracture had advected ∼500 m from the lake's deepest point, meaning the lake did not fully drain. Partial drainage events have previously been assumed to occur slowly via lake overtopping, with a comparatively small dynamic influence. In contrast, our findings show that partial drainage events can be caused by hydrofracture, producing new hydrological connections that continue to concentrate the supply of surface meltwater to the bed of the ice sheet throughout the melt season. Our findings therefore indicate that the quantity and resultant dynamic influence of rapid lake drainages are likely being underestimated. This research was funded by the European Research Council as part of the RESPONDER project under the European Union’s Horizon 2020 research and innovation programme (grant 683043). TRC was supported by a Natural Environment Research Council Doctoral Training Partnership Studentship (grant NE/L002507/1). |
format |
Article in Journal/Newspaper |
author |
Chudley, Thomas R Christoffersen, Poul Doyle, Samuel H Bougamont, Marion Schoonman, Charlotte M Hubbard, Bryn James, Mike R |
author_facet |
Chudley, Thomas R Christoffersen, Poul Doyle, Samuel H Bougamont, Marion Schoonman, Charlotte M Hubbard, Bryn James, Mike R |
author_sort |
Chudley, Thomas R |
title |
Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. |
title_short |
Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. |
title_full |
Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. |
title_fullStr |
Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. |
title_full_unstemmed |
Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. |
title_sort |
supraglacial lake drainage at a fast-flowing greenlandic outlet glacier. |
publisher |
Proceedings of the National Academy of Sciences |
publishDate |
2019 |
url |
https://www.repository.cam.ac.uk/handle/1810/299570 https://doi.org/10.17863/CAM.46643 |
long_lat |
ENVELOPE(177.619,177.619,52.064,52.064) |
geographic |
Greenland Rapid Lake |
geographic_facet |
Greenland Rapid Lake |
genre |
glacier Greenland greenlandic Ice Sheet |
genre_facet |
glacier Greenland greenlandic Ice Sheet |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/299570 doi:10.17863/CAM.46643 |
op_doi |
https://doi.org/10.17863/CAM.46643 |
_version_ |
1789965929965158400 |