Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway
Glacier thermal regime is shown to have a significant influence on the formation of ice‐marginal moraines. Annual moraines at the margin of Midtdalsbreen are asymmetrical and contain sorted fine sediment and diamicton layers dipping gently up‐glacier. The sorted fine sediments include sands and grav...
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crwiley:10.1111/bor.12008 2024-06-23T07:53:04+00:00 Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway Reinardy, Benedict T. I. Leighton, Iain Marx, Peter J. 2013 http://dx.doi.org/10.1111/bor.12008 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12008 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12008 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Boreas volume 42, issue 4, page 896-911 ISSN 0300-9483 1502-3885 journal-article 2013 crwiley https://doi.org/10.1111/bor.12008 2024-06-11T04:47:49Z Glacier thermal regime is shown to have a significant influence on the formation of ice‐marginal moraines. Annual moraines at the margin of Midtdalsbreen are asymmetrical and contain sorted fine sediment and diamicton layers dipping gently up‐glacier. The sorted fine sediments include sands and gravels that were initially deposited fluvially directly in front of the glacier. Clast‐form data indicate that the diamictons have a mixed subglacial and fluvial origin. Winter cold is able to penetrate through the thin (<10 m) ice margin and freeze these sediments to the glacier sole. During winter, sediment becomes elevated along the wedge‐shaped advancing glacier snout before melting out and being deposited as asymmetrical ridges. These annual moraines have a limited preservation potential of ∼40 years, and this is reflected in the evolution of landforms across the glacier foreland. Despite changing climatic conditions since the L ittle I ce A ge and particularly within the last 10 years when frontal retreat has significantly speeded up, glacier dynamics have remained relatively constant with moraines deposited via basal freeze‐on, which requires stable glacier geometry. While the annual moraines on the eastern side of M idtdalsbreen indicate a slow steady retreat, the western foreland contains contrasting ice‐stagnation topography, highlighting the importance of local forcing factors such as shielding, aspect and debris cover in addition to changing climate. This study indicates that, even in temperate glacial environments, restricted or localised areas of cold‐based ice can have a significant impact on the geomorphic imprint of the glacier system and may actually be more widespread within both modern and ancient glacial environments than previously thought. Article in Journal/Newspaper glacier Wiley Online Library Norway Boreas n/a n/a |
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Wiley Online Library |
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English |
description |
Glacier thermal regime is shown to have a significant influence on the formation of ice‐marginal moraines. Annual moraines at the margin of Midtdalsbreen are asymmetrical and contain sorted fine sediment and diamicton layers dipping gently up‐glacier. The sorted fine sediments include sands and gravels that were initially deposited fluvially directly in front of the glacier. Clast‐form data indicate that the diamictons have a mixed subglacial and fluvial origin. Winter cold is able to penetrate through the thin (<10 m) ice margin and freeze these sediments to the glacier sole. During winter, sediment becomes elevated along the wedge‐shaped advancing glacier snout before melting out and being deposited as asymmetrical ridges. These annual moraines have a limited preservation potential of ∼40 years, and this is reflected in the evolution of landforms across the glacier foreland. Despite changing climatic conditions since the L ittle I ce A ge and particularly within the last 10 years when frontal retreat has significantly speeded up, glacier dynamics have remained relatively constant with moraines deposited via basal freeze‐on, which requires stable glacier geometry. While the annual moraines on the eastern side of M idtdalsbreen indicate a slow steady retreat, the western foreland contains contrasting ice‐stagnation topography, highlighting the importance of local forcing factors such as shielding, aspect and debris cover in addition to changing climate. This study indicates that, even in temperate glacial environments, restricted or localised areas of cold‐based ice can have a significant impact on the geomorphic imprint of the glacier system and may actually be more widespread within both modern and ancient glacial environments than previously thought. |
format |
Article in Journal/Newspaper |
author |
Reinardy, Benedict T. I. Leighton, Iain Marx, Peter J. |
spellingShingle |
Reinardy, Benedict T. I. Leighton, Iain Marx, Peter J. Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway |
author_facet |
Reinardy, Benedict T. I. Leighton, Iain Marx, Peter J. |
author_sort |
Reinardy, Benedict T. I. |
title |
Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway |
title_short |
Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway |
title_full |
Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway |
title_fullStr |
Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway |
title_full_unstemmed |
Glacier thermal regime linked to processes of annual moraine formation at Midtdalsbreen, southern Norway |
title_sort |
glacier thermal regime linked to processes of annual moraine formation at midtdalsbreen, southern norway |
publisher |
Wiley |
publishDate |
2013 |
url |
http://dx.doi.org/10.1111/bor.12008 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12008 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12008 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
glacier |
genre_facet |
glacier |
op_source |
Boreas volume 42, issue 4, page 896-911 ISSN 0300-9483 1502-3885 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/bor.12008 |
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Boreas |
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1802644539778793472 |