Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier
Abstract Frontal ablation, the combination of submarine melting and iceberg calving, changes the geometry of a glacier's terminus, influencing glacier dynamics, the fate of upwelling plumes and the distribution of submarine meltwater input into the ocean. Directly observing frontal ablation and...
Published in: | Annals of Glaciology |
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Language: | English |
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Cambridge University Press (CUP)
2023
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Online Access: | http://dx.doi.org/10.1017/aog.2023.38 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305523000381 |
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crcambridgeupr:10.1017/aog.2023.38 2024-06-23T07:45:36+00:00 Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier Abib, Nicole Sutherland, David A. Amundson, Jason M. Duncan, Dan Eidam, Emily F. Jackson, Rebecca H. Kienholz, Christian Morlighem, Mathieu Motyka, Roman J. Nash, Jonathan D. Ovall, Bridget Pettit, Erin C. Office of Polar Programs Office of Polar Programs Office of Polar Programs Office of Polar Programs Office of Polar Programs 2023 http://dx.doi.org/10.1017/aog.2023.38 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305523000381 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Annals of Glaciology volume 64, issue 90, page 1-12 ISSN 0260-3055 1727-5644 journal-article 2023 crcambridgeupr https://doi.org/10.1017/aog.2023.38 2024-05-29T08:08:20Z Abstract Frontal ablation, the combination of submarine melting and iceberg calving, changes the geometry of a glacier's terminus, influencing glacier dynamics, the fate of upwelling plumes and the distribution of submarine meltwater input into the ocean. Directly observing frontal ablation and terminus morphology below the waterline is difficult, however, limiting our understanding of these coupled ice–ocean processes. To investigate the evolution of a tidewater glacier's submarine terminus, we combine 3-D multibeam point clouds of the subsurface ice face at LeConte Glacier, Alaska, with concurrent observations of environmental conditions during three field campaigns between 2016 and 2018. We observe terminus morphology that was predominately overcut (52% in August 2016, 63% in May 2017 and 74% in September 2018), accompanied by high multibeam sonar-derived melt rates (4.84 m d −1 in 2016, 1.13 m d −1 in 2017 and 1.85 m d −1 in 2018). We find that periods of high subglacial discharge lead to localized undercut discharge outlets, but adjacent to these outlets the terminus maintains significantly overcut geometry, with an ice ramp that protrudes 75 m into the fjord in 2017 and 125 m in 2018. Our data challenge the assumption that tidewater glacier termini are largely undercut during periods of high submarine melting. Article in Journal/Newspaper Annals of Glaciology glacier Tidewater Alaska Cambridge University Press Annals of Glaciology 64 90 1 12 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract Frontal ablation, the combination of submarine melting and iceberg calving, changes the geometry of a glacier's terminus, influencing glacier dynamics, the fate of upwelling plumes and the distribution of submarine meltwater input into the ocean. Directly observing frontal ablation and terminus morphology below the waterline is difficult, however, limiting our understanding of these coupled ice–ocean processes. To investigate the evolution of a tidewater glacier's submarine terminus, we combine 3-D multibeam point clouds of the subsurface ice face at LeConte Glacier, Alaska, with concurrent observations of environmental conditions during three field campaigns between 2016 and 2018. We observe terminus morphology that was predominately overcut (52% in August 2016, 63% in May 2017 and 74% in September 2018), accompanied by high multibeam sonar-derived melt rates (4.84 m d −1 in 2016, 1.13 m d −1 in 2017 and 1.85 m d −1 in 2018). We find that periods of high subglacial discharge lead to localized undercut discharge outlets, but adjacent to these outlets the terminus maintains significantly overcut geometry, with an ice ramp that protrudes 75 m into the fjord in 2017 and 125 m in 2018. Our data challenge the assumption that tidewater glacier termini are largely undercut during periods of high submarine melting. |
author2 |
Office of Polar Programs Office of Polar Programs Office of Polar Programs Office of Polar Programs Office of Polar Programs |
format |
Article in Journal/Newspaper |
author |
Abib, Nicole Sutherland, David A. Amundson, Jason M. Duncan, Dan Eidam, Emily F. Jackson, Rebecca H. Kienholz, Christian Morlighem, Mathieu Motyka, Roman J. Nash, Jonathan D. Ovall, Bridget Pettit, Erin C. |
spellingShingle |
Abib, Nicole Sutherland, David A. Amundson, Jason M. Duncan, Dan Eidam, Emily F. Jackson, Rebecca H. Kienholz, Christian Morlighem, Mathieu Motyka, Roman J. Nash, Jonathan D. Ovall, Bridget Pettit, Erin C. Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
author_facet |
Abib, Nicole Sutherland, David A. Amundson, Jason M. Duncan, Dan Eidam, Emily F. Jackson, Rebecca H. Kienholz, Christian Morlighem, Mathieu Motyka, Roman J. Nash, Jonathan D. Ovall, Bridget Pettit, Erin C. |
author_sort |
Abib, Nicole |
title |
Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
title_short |
Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
title_full |
Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
title_fullStr |
Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
title_full_unstemmed |
Persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
title_sort |
persistent overcut regions dominate the terminus morphology of a rapidly melting tidewater glacier |
publisher |
Cambridge University Press (CUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1017/aog.2023.38 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305523000381 |
genre |
Annals of Glaciology glacier Tidewater Alaska |
genre_facet |
Annals of Glaciology glacier Tidewater Alaska |
op_source |
Annals of Glaciology volume 64, issue 90, page 1-12 ISSN 0260-3055 1727-5644 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/aog.2023.38 |
container_title |
Annals of Glaciology |
container_volume |
64 |
container_issue |
90 |
container_start_page |
1 |
op_container_end_page |
12 |
_version_ |
1802641412581228544 |