Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet
Abstract In this paper we report on observations of glacial landscapes at the head of geomorphologically interpreted palaeo‐ice streams, i.e. palaeo‐ice‐stream onsets. Our work is based on the results of systematic palaeoglaciological mapping of the portion of north‐eastern Canada formerly covered b...
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crwiley:10.1002/esp.1663 2024-06-02T08:08:15+00:00 Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet Angelis, Hernán De Kleman, Johan 2008 http://dx.doi.org/10.1002/esp.1663 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.1663 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.1663 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Earth Surface Processes and Landforms volume 33, issue 4, page 560-572 ISSN 0197-9337 1096-9837 journal-article 2008 crwiley https://doi.org/10.1002/esp.1663 2024-05-03T10:53:35Z Abstract In this paper we report on observations of glacial landscapes at the head of geomorphologically interpreted palaeo‐ice streams, i.e. palaeo‐ice‐stream onsets. Our work is based on the results of systematic palaeoglaciological mapping of the portion of north‐eastern Canada formerly covered by the Laurentide Ice Sheet. Four different cases are considered and analysed in detail: one is the Dubawnt Lake Ice Stream and the others are smaller (<70 km long) palaeo‐ice streams. We found that in this region onset zones are generally characterized by a heterogeneous landform record and are more easily recognized when landscapes typical of partially frozen beds are present. Based on publicly available topographical and geological data as well as theoretical developments, we discuss the conditions and controls on the location of these onset zones and their potential stability. Except for the Dubawnt Lake Ice Stream, we found that, although topography and geology are important conditioning factors, the geomorphological imprint of palaeo‐ice‐stream onsets cannot be explained without invoking the role of the basal thermal boundary between cold‐ and warm‐based ice. Finally, we observed that, except for the Dubawnt Lake Ice Stream, the onset zones of large ice streams are rarely preserved, and we suggest two possible explanations for this. We conclude that although the same qualitative processes are present under the majority of ice streams, conditions for the preservation of the onset zones are more likely to be met in the case of relatively small ice streams because these are more rapidly deglaciated. Copyright © 2008 John Wiley & Sons, Ltd. Article in Journal/Newspaper Ice Sheet Wiley Online Library Canada Dubawnt Lake ENVELOPE(-102.096,-102.096,63.063,63.063) Earth Surface Processes and Landforms 33 4 560 572 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract In this paper we report on observations of glacial landscapes at the head of geomorphologically interpreted palaeo‐ice streams, i.e. palaeo‐ice‐stream onsets. Our work is based on the results of systematic palaeoglaciological mapping of the portion of north‐eastern Canada formerly covered by the Laurentide Ice Sheet. Four different cases are considered and analysed in detail: one is the Dubawnt Lake Ice Stream and the others are smaller (<70 km long) palaeo‐ice streams. We found that in this region onset zones are generally characterized by a heterogeneous landform record and are more easily recognized when landscapes typical of partially frozen beds are present. Based on publicly available topographical and geological data as well as theoretical developments, we discuss the conditions and controls on the location of these onset zones and their potential stability. Except for the Dubawnt Lake Ice Stream, we found that, although topography and geology are important conditioning factors, the geomorphological imprint of palaeo‐ice‐stream onsets cannot be explained without invoking the role of the basal thermal boundary between cold‐ and warm‐based ice. Finally, we observed that, except for the Dubawnt Lake Ice Stream, the onset zones of large ice streams are rarely preserved, and we suggest two possible explanations for this. We conclude that although the same qualitative processes are present under the majority of ice streams, conditions for the preservation of the onset zones are more likely to be met in the case of relatively small ice streams because these are more rapidly deglaciated. Copyright © 2008 John Wiley & Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
Angelis, Hernán De Kleman, Johan |
spellingShingle |
Angelis, Hernán De Kleman, Johan Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet |
author_facet |
Angelis, Hernán De Kleman, Johan |
author_sort |
Angelis, Hernán De |
title |
Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet |
title_short |
Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet |
title_full |
Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet |
title_fullStr |
Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet |
title_full_unstemmed |
Palaeo‐ice‐stream onsets: examples from the north‐eastern Laurentide Ice Sheet |
title_sort |
palaeo‐ice‐stream onsets: examples from the north‐eastern laurentide ice sheet |
publisher |
Wiley |
publishDate |
2008 |
url |
http://dx.doi.org/10.1002/esp.1663 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.1663 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.1663 |
long_lat |
ENVELOPE(-102.096,-102.096,63.063,63.063) |
geographic |
Canada Dubawnt Lake |
geographic_facet |
Canada Dubawnt Lake |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Earth Surface Processes and Landforms volume 33, issue 4, page 560-572 ISSN 0197-9337 1096-9837 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/esp.1663 |
container_title |
Earth Surface Processes and Landforms |
container_volume |
33 |
container_issue |
4 |
container_start_page |
560 |
op_container_end_page |
572 |
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1800753455506128896 |