Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet
Abstract High-resolution digital elevation models of Finland and Sweden based on LiDAR (Light Detection and Ranging) reveal subglacial landforms in great detail. We describe the ice-sheet scale distribution and morphometric characteristics of a glacial landform that is distinctive in morphology and...
Published in: | Annals of Glaciology |
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Language: | English |
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Cambridge University Press (CUP)
2019
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Online Access: | http://dx.doi.org/10.1017/aog.2019.34 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S026030551900034X |
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crcambridgeupr:10.1017/aog.2019.34 2024-06-09T07:38:31+00:00 Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet Ojala, Antti E. K. Peterson, Gustaf Mäkinen, Joni Johnson, Mark D. Kajuutti, Kari Palmu, Jukka-Pekka Ahokangas, Elina Öhrling, Christian 2019 http://dx.doi.org/10.1017/aog.2019.34 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S026030551900034X en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Annals of Glaciology volume 60, issue 80, page 115-126 ISSN 0260-3055 1727-5644 journal-article 2019 crcambridgeupr https://doi.org/10.1017/aog.2019.34 2024-05-15T13:14:51Z Abstract High-resolution digital elevation models of Finland and Sweden based on LiDAR (Light Detection and Ranging) reveal subglacial landforms in great detail. We describe the ice-sheet scale distribution and morphometric characteristics of a glacial landform that is distinctive in morphology and occurs commonly in the central parts of the former Scandinavian Ice Sheet, especially up-ice of the Younger Dryas end moraine zone. We refer to these triangular or V-shaped landforms as murtoos (singular, ‘murtoo’). Murtoos are typically 30–200 m in length and 30–200 m in width with a relief of commonly <5 m. Murtoos have straight and steep edges, a triangular tip oriented parallel to ice-flow direction, and an asymmetric longitudinal profile with a shorter, but steeper down-ice slope. The spatial distribution of murtoos and their geomorphic relation to other landforms indicate that they formed subglacially during times of climate warming and rapid retreat of the Scandinavian Ice Sheet when large amounts of meltwater were delivered to the bed. Murtoos are formed under warm-based ice and may be associated with a non-channelized subglacial hydraulic system that evacuated large discharges of subglacial water. Article in Journal/Newspaper Annals of Glaciology Ice Sheet Cambridge University Press Annals of Glaciology 60 80 115 126 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
Abstract High-resolution digital elevation models of Finland and Sweden based on LiDAR (Light Detection and Ranging) reveal subglacial landforms in great detail. We describe the ice-sheet scale distribution and morphometric characteristics of a glacial landform that is distinctive in morphology and occurs commonly in the central parts of the former Scandinavian Ice Sheet, especially up-ice of the Younger Dryas end moraine zone. We refer to these triangular or V-shaped landforms as murtoos (singular, ‘murtoo’). Murtoos are typically 30–200 m in length and 30–200 m in width with a relief of commonly <5 m. Murtoos have straight and steep edges, a triangular tip oriented parallel to ice-flow direction, and an asymmetric longitudinal profile with a shorter, but steeper down-ice slope. The spatial distribution of murtoos and their geomorphic relation to other landforms indicate that they formed subglacially during times of climate warming and rapid retreat of the Scandinavian Ice Sheet when large amounts of meltwater were delivered to the bed. Murtoos are formed under warm-based ice and may be associated with a non-channelized subglacial hydraulic system that evacuated large discharges of subglacial water. |
format |
Article in Journal/Newspaper |
author |
Ojala, Antti E. K. Peterson, Gustaf Mäkinen, Joni Johnson, Mark D. Kajuutti, Kari Palmu, Jukka-Pekka Ahokangas, Elina Öhrling, Christian |
spellingShingle |
Ojala, Antti E. K. Peterson, Gustaf Mäkinen, Joni Johnson, Mark D. Kajuutti, Kari Palmu, Jukka-Pekka Ahokangas, Elina Öhrling, Christian Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet |
author_facet |
Ojala, Antti E. K. Peterson, Gustaf Mäkinen, Joni Johnson, Mark D. Kajuutti, Kari Palmu, Jukka-Pekka Ahokangas, Elina Öhrling, Christian |
author_sort |
Ojala, Antti E. K. |
title |
Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet |
title_short |
Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet |
title_full |
Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet |
title_fullStr |
Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet |
title_full_unstemmed |
Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet |
title_sort |
ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the scandinavian ice sheet |
publisher |
Cambridge University Press (CUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1017/aog.2019.34 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S026030551900034X |
genre |
Annals of Glaciology Ice Sheet |
genre_facet |
Annals of Glaciology Ice Sheet |
op_source |
Annals of Glaciology volume 60, issue 80, page 115-126 ISSN 0260-3055 1727-5644 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/aog.2019.34 |
container_title |
Annals of Glaciology |
container_volume |
60 |
container_issue |
80 |
container_start_page |
115 |
op_container_end_page |
126 |
_version_ |
1801373378887548928 |