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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ftpubmed:oai:pubmedcentral.nih.gov:6926039 2023-05-15T16:21:17+02:00 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 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926039/ http://www.ncbi.nlm.nih.gov/pubmed/31792177 https://doi.org/10.1073/pnas.1913685116 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926039/ http://www.ncbi.nlm.nih.gov/pubmed/31792177 http://dx.doi.org/10.1073/pnas.1913685116 https://www.pnas.org/site/aboutpnas/licenses.xhtmlPublished under the PNAS license (https://www.pnas.org/site/aboutpnas/licenses.xhtml) . Proc Natl Acad Sci U S A Physical Sciences Text 2019 ftpubmed https://doi.org/10.1073/pnas.1913685116 2020-06-07T00:28:28Z 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 [Formula: see text] 10(6) m(3) of meltwater to the glacier bed in [Formula: see text] 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 [Formula: see text] d(−1) to 5.3 m [Formula: see text] d(−1). Dynamic responses were greatest [Formula: see text] 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 [Formula: see text] 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. Text glacier Greenland greenlandic Ice Sheet PubMed Central (PMC) Greenland Rapid Lake ENVELOPE(177.619,177.619,52.064,52.064) Proceedings of the National Academy of Sciences 116 51 25468 25477 |
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English |
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Physical Sciences |
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Physical Sciences 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 |
Physical Sciences |
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 [Formula: see text] 10(6) m(3) of meltwater to the glacier bed in [Formula: see text] 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 [Formula: see text] d(−1) to 5.3 m [Formula: see text] d(−1). Dynamic responses were greatest [Formula: see text] 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 [Formula: see text] 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. |
format |
Text |
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 |
National Academy of Sciences |
publishDate |
2019 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926039/ http://www.ncbi.nlm.nih.gov/pubmed/31792177 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_source |
Proc Natl Acad Sci U S A |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926039/ http://www.ncbi.nlm.nih.gov/pubmed/31792177 http://dx.doi.org/10.1073/pnas.1913685116 |
op_rights |
https://www.pnas.org/site/aboutpnas/licenses.xhtmlPublished under the PNAS license (https://www.pnas.org/site/aboutpnas/licenses.xhtml) . |
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 |
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1766009290200449024 |