Undercutting of marine‐terminating glaciers in West Greenland
Marine‐terminating glaciers control most of Greenland's ice discharge into the ocean, but little is known about the geometry of their frontal regions. Here we use side‐looking, multibeam echo sounding observations to reveal that their frontal ice cliffs are grounded deeper below sea level than...
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ftpubmed:oai:pubmedcentral.nih.gov:6473555 2023-05-15T16:21:10+02:00 Undercutting of marine‐terminating glaciers in West Greenland Rignot, Eric Fenty, Ian Xu, Yun Cai, Cilan Kemp, Chris 2015-07-27 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473555/ https://doi.org/10.1002/2015GL064236 en eng John Wiley and Sons Inc. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473555/ http://dx.doi.org/10.1002/2015GL064236 ©2015. The Authors. This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. CC-BY-NC-ND Research Letters Text 2015 ftpubmed https://doi.org/10.1002/2015GL064236 2019-04-28T00:25:04Z Marine‐terminating glaciers control most of Greenland's ice discharge into the ocean, but little is known about the geometry of their frontal regions. Here we use side‐looking, multibeam echo sounding observations to reveal that their frontal ice cliffs are grounded deeper below sea level than previously measured and their ice faces are neither vertical nor smooth but often undercut by the ocean and rough. Deep glacier grounding enables contact with subsurface, warm, salty Atlantic waters (AW) which melts ice at rates of meters per day. We detect cavities undercutting the base of the calving faces at the sites of subglacial water (SGW) discharge predicted by a hydrological model. The observed pattern of undercutting is consistent with numerical simulations of ice melt in which buoyant plumes of SGW transport warm AW to the ice faces. Glacier undercutting likely enhances iceberg calving, impacting ice front stability and, in turn, the glacier mass balance. Text glacier Greenland PubMed Central (PMC) Greenland Geophysical Research Letters 42 14 5909 5917 |
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Research Letters |
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Research Letters Rignot, Eric Fenty, Ian Xu, Yun Cai, Cilan Kemp, Chris Undercutting of marine‐terminating glaciers in West Greenland |
topic_facet |
Research Letters |
description |
Marine‐terminating glaciers control most of Greenland's ice discharge into the ocean, but little is known about the geometry of their frontal regions. Here we use side‐looking, multibeam echo sounding observations to reveal that their frontal ice cliffs are grounded deeper below sea level than previously measured and their ice faces are neither vertical nor smooth but often undercut by the ocean and rough. Deep glacier grounding enables contact with subsurface, warm, salty Atlantic waters (AW) which melts ice at rates of meters per day. We detect cavities undercutting the base of the calving faces at the sites of subglacial water (SGW) discharge predicted by a hydrological model. The observed pattern of undercutting is consistent with numerical simulations of ice melt in which buoyant plumes of SGW transport warm AW to the ice faces. Glacier undercutting likely enhances iceberg calving, impacting ice front stability and, in turn, the glacier mass balance. |
format |
Text |
author |
Rignot, Eric Fenty, Ian Xu, Yun Cai, Cilan Kemp, Chris |
author_facet |
Rignot, Eric Fenty, Ian Xu, Yun Cai, Cilan Kemp, Chris |
author_sort |
Rignot, Eric |
title |
Undercutting of marine‐terminating glaciers in West Greenland |
title_short |
Undercutting of marine‐terminating glaciers in West Greenland |
title_full |
Undercutting of marine‐terminating glaciers in West Greenland |
title_fullStr |
Undercutting of marine‐terminating glaciers in West Greenland |
title_full_unstemmed |
Undercutting of marine‐terminating glaciers in West Greenland |
title_sort |
undercutting of marine‐terminating glaciers in west greenland |
publisher |
John Wiley and Sons Inc. |
publishDate |
2015 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473555/ https://doi.org/10.1002/2015GL064236 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland |
genre_facet |
glacier Greenland |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473555/ http://dx.doi.org/10.1002/2015GL064236 |
op_rights |
©2015. The Authors. This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1002/2015GL064236 |
container_title |
Geophysical Research Letters |
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42 |
container_issue |
14 |
container_start_page |
5909 |
op_container_end_page |
5917 |
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1766009191784251392 |