Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet
Murtoos are recently discovered triangular‐shaped subglacial landforms that form under warm‐based ice and in association with significant subglacial meltwater flow. They appear in distinct fields and commonly occur in the area that was covered by the Fennoscandian Ice Sheet during glacial periods. M...
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crwiley:10.1111/bor.12526 2024-09-15T18:06:04+00:00 Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet Ojala, Antti E. K. Mäkinen, Joni Ahokangas, Elina Kajuutti, Kari Valkama, Markus Tuunainen, Aleksi Palmu, Jukka‐Pekka Luonnontieteiden ja Tekniikan Tutkimuksen Toimikunta 2021 http://dx.doi.org/10.1111/bor.12526 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12526 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12526 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Boreas volume 50, issue 4, page 1095-1115 ISSN 0300-9483 1502-3885 journal-article 2021 crwiley https://doi.org/10.1111/bor.12526 2024-08-30T04:09:50Z Murtoos are recently discovered triangular‐shaped subglacial landforms that form under warm‐based ice and in association with significant subglacial meltwater flow. They appear in distinct fields and commonly occur in the area that was covered by the Fennoscandian Ice Sheet during glacial periods. Murtoos potentially represent a transition form from non‐channelized to channelized subglacial drainage networks. In the present study, we analyse and classify murtoos and murtoo‐related landforms in the Finnish area of the Fennoscandian Ice Sheet based on their characteristics and appearance in LiDAR‐based digital elevations models. Combined with morphometric analyses, the observations suggest that five types of murtoos and murtoo‐related landforms are common and widespread in Finland: (i) triangle‐type murtoos (TTMs), (ii) chevron‐type murtoos (CTMs), (iii) lobate‐type murtoos (LTMs), (iv) murtoo‐related ridges and escarpments (MREs), and (v) other murtoo‐related polymorphous landforms (PMRs) that look like small mounds and ridges. The morphometric characteristics of the different types are described here in detail, and it is shown that they are spatially and geomorphologically related. In addition, we provide examples of murtoos other than the TTMs to demonstrate that different murtoo types and murtoo‐related landforms are composed of similar sediments and architectural characteristics. The diversity of murtoo landforms and the transition between distinct murtoo types indicate rapid and complicated variations in the configuration of subglacial hydrology at different spatial and temporal scales. This study emphasizes the essential role of subglacial meltwater in the shaping of glacial landscapes and the redistribution of large volumes of sediments during the deglaciation of the Fennoscandian Ice Sheet. Article in Journal/Newspaper Fennoscandian Ice Sheet Wiley Online Library Boreas |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Murtoos are recently discovered triangular‐shaped subglacial landforms that form under warm‐based ice and in association with significant subglacial meltwater flow. They appear in distinct fields and commonly occur in the area that was covered by the Fennoscandian Ice Sheet during glacial periods. Murtoos potentially represent a transition form from non‐channelized to channelized subglacial drainage networks. In the present study, we analyse and classify murtoos and murtoo‐related landforms in the Finnish area of the Fennoscandian Ice Sheet based on their characteristics and appearance in LiDAR‐based digital elevations models. Combined with morphometric analyses, the observations suggest that five types of murtoos and murtoo‐related landforms are common and widespread in Finland: (i) triangle‐type murtoos (TTMs), (ii) chevron‐type murtoos (CTMs), (iii) lobate‐type murtoos (LTMs), (iv) murtoo‐related ridges and escarpments (MREs), and (v) other murtoo‐related polymorphous landforms (PMRs) that look like small mounds and ridges. The morphometric characteristics of the different types are described here in detail, and it is shown that they are spatially and geomorphologically related. In addition, we provide examples of murtoos other than the TTMs to demonstrate that different murtoo types and murtoo‐related landforms are composed of similar sediments and architectural characteristics. The diversity of murtoo landforms and the transition between distinct murtoo types indicate rapid and complicated variations in the configuration of subglacial hydrology at different spatial and temporal scales. This study emphasizes the essential role of subglacial meltwater in the shaping of glacial landscapes and the redistribution of large volumes of sediments during the deglaciation of the Fennoscandian Ice Sheet. |
author2 |
Luonnontieteiden ja Tekniikan Tutkimuksen Toimikunta |
format |
Article in Journal/Newspaper |
author |
Ojala, Antti E. K. Mäkinen, Joni Ahokangas, Elina Kajuutti, Kari Valkama, Markus Tuunainen, Aleksi Palmu, Jukka‐Pekka |
spellingShingle |
Ojala, Antti E. K. Mäkinen, Joni Ahokangas, Elina Kajuutti, Kari Valkama, Markus Tuunainen, Aleksi Palmu, Jukka‐Pekka Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet |
author_facet |
Ojala, Antti E. K. Mäkinen, Joni Ahokangas, Elina Kajuutti, Kari Valkama, Markus Tuunainen, Aleksi Palmu, Jukka‐Pekka |
author_sort |
Ojala, Antti E. K. |
title |
Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet |
title_short |
Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet |
title_full |
Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet |
title_fullStr |
Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet |
title_full_unstemmed |
Diversity of murtoos and murtoo‐related subglacial landforms in the Finnish area of the Fennoscandian Ice Sheet |
title_sort |
diversity of murtoos and murtoo‐related subglacial landforms in the finnish area of the fennoscandian ice sheet |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1111/bor.12526 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12526 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12526 |
genre |
Fennoscandian Ice Sheet |
genre_facet |
Fennoscandian Ice Sheet |
op_source |
Boreas volume 50, issue 4, page 1095-1115 ISSN 0300-9483 1502-3885 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1111/bor.12526 |
container_title |
Boreas |
_version_ |
1810443567269675008 |