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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ftulancaster:oai:eprints.lancs.ac.uk:140569 2023-08-27T04:09:35+02:00 Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier Chudley, Thomas Christoffersen, Poul Doyle, Samuel Bougamont, Marion Schoonman, Charlotte Hubbard, Bryn James, Michael 2019-12-17 text https://eprints.lancs.ac.uk/id/eprint/140569/ https://eprints.lancs.ac.uk/id/eprint/140569/1/476347_1_merged_1571836079_author_accepted.pdf https://doi.org/10.1073/pnas.1913685116 en eng https://eprints.lancs.ac.uk/id/eprint/140569/1/476347_1_merged_1571836079_author_accepted.pdf Chudley, Thomas and Christoffersen, Poul and Doyle, Samuel and Bougamont, Marion and Schoonman, Charlotte and Hubbard, Bryn and James, Michael (2019) Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. Proceedings of the National Academy of Sciences of the United States of America, 116 (51). pp. 25468-25477. ISSN 0027-8424 creative_commons_attribution_noncommercial_4_0_international_license Journal Article PeerReviewed 2019 ftulancaster https://doi.org/10.1073/pnas.1913685116 2023-08-03T22:37:31Z 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 x 10(6) m(3) of meltwater to the glacier bed in similar to 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 similar to 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 similar to 500 m from the lakes 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. Article in Journal/Newspaper glacier Greenland greenlandic Ice Sheet Lancaster University: Lancaster Eprints Greenland Rapid Lake ENVELOPE(177.619,177.619,52.064,52.064) Proceedings of the National Academy of Sciences 116 51 25468 25477 |
institution |
Open Polar |
collection |
Lancaster University: Lancaster Eprints |
op_collection_id |
ftulancaster |
language |
English |
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 x 10(6) m(3) of meltwater to the glacier bed in similar to 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 similar to 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 similar to 500 m from the lakes 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. |
format |
Article in Journal/Newspaper |
author |
Chudley, Thomas Christoffersen, Poul Doyle, Samuel Bougamont, Marion Schoonman, Charlotte Hubbard, Bryn James, Michael |
spellingShingle |
Chudley, Thomas Christoffersen, Poul Doyle, Samuel Bougamont, Marion Schoonman, Charlotte Hubbard, Bryn James, Michael Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier |
author_facet |
Chudley, Thomas Christoffersen, Poul Doyle, Samuel Bougamont, Marion Schoonman, Charlotte Hubbard, Bryn James, Michael |
author_sort |
Chudley, Thomas |
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 |
publishDate |
2019 |
url |
https://eprints.lancs.ac.uk/id/eprint/140569/ https://eprints.lancs.ac.uk/id/eprint/140569/1/476347_1_merged_1571836079_author_accepted.pdf https://doi.org/10.1073/pnas.1913685116 |
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://eprints.lancs.ac.uk/id/eprint/140569/1/476347_1_merged_1571836079_author_accepted.pdf Chudley, Thomas and Christoffersen, Poul and Doyle, Samuel and Bougamont, Marion and Schoonman, Charlotte and Hubbard, Bryn and James, Michael (2019) Supraglacial lake drainage at a fast-flowing Greenlandic outlet glacier. Proceedings of the National Academy of Sciences of the United States of America, 116 (51). pp. 25468-25477. ISSN 0027-8424 |
op_rights |
creative_commons_attribution_noncommercial_4_0_international_license |
op_doi |
https://doi.org/10.1073/pnas.1913685116 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
116 |
container_issue |
51 |
container_start_page |
25468 |
op_container_end_page |
25477 |
_version_ |
1775351092728561664 |