Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic
International audience Thermokarst lakes are widespread and diverse across permafrost regions, and they are considered significant contributors to global greenhouse gas emissions. Paleoenvironmental reconstructions documenting the inception and development of these ecologically important water bodie...
Published in: | The Cryosphere |
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ftunivnantes:oai:HAL:insu-03745266v1 2023-05-15T14:56:34+02:00 Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic Bouchard, Frédéric Fortier, Daniel Paquette, Michel Boucher, Vincent Pienitz, Reinhard Laurion, Isabelle Géosciences Paris Saclay (GEOPS) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) 2020 https://hal-insu.archives-ouvertes.fr/insu-03745266 https://hal-insu.archives-ouvertes.fr/insu-03745266/document https://hal-insu.archives-ouvertes.fr/insu-03745266/file/tc-14-2607-2020.pdf https://doi.org/10.5194/tc-14-2607-2020 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-14-2607-2020 insu-03745266 https://hal-insu.archives-ouvertes.fr/insu-03745266 https://hal-insu.archives-ouvertes.fr/insu-03745266/document https://hal-insu.archives-ouvertes.fr/insu-03745266/file/tc-14-2607-2020.pdf BIBCODE: 2020TCry.14.2607B doi:10.5194/tc-14-2607-2020 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess The Cryosphere https://hal-insu.archives-ouvertes.fr/insu-03745266 The Cryosphere, 2020, 14, pp.2607-2627. ⟨10.5194/tc-14-2607-2020⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2020 ftunivnantes https://doi.org/10.5194/tc-14-2607-2020 2022-08-09T23:35:04Z International audience Thermokarst lakes are widespread and diverse across permafrost regions, and they are considered significant contributors to global greenhouse gas emissions. Paleoenvironmental reconstructions documenting the inception and development of these ecologically important water bodies are generally limited to Pleistocene-age permafrost deposits of Siberia, Alaska, and the western Canadian Arctic. Here we present the gradual transition from syngenetic ice-wedge polygon terrain to a thermokarst lake in Holocene sediments of the eastern Canadian Arctic. We combine geomorphological surveys with paleolimnological reconstructions from sediment cores in an effort to characterize local landscape evolution from a terrestrial to freshwater environment. Located on an ice- and organic-rich polygonal terrace, the studied lake is now evolving through active thermokarst, as revealed by subsiding and eroding shores, and was likely created by water pooling within a pre-existing topographic depression. Organic sedimentation in the valley started during the mid-Holocene, as documented by the oldest organic debris found at the base of one sediment core and dated at 4.8 kyr BP. Local sedimentation dynamics were initially controlled by fluctuations in wind activity, local moisture, and vegetation growth and accumulation, as shown by alternating loess (silt) and peat layers. Fossil diatom assemblages were likewise influenced by local hydro-climatic conditions and reflect a broad range of substrates available in the past (both terrestrial and aquatic). Such conditions likely prevailed until ∼2000 BP, when peat accumulation stopped as water ponded the surface of degrading ice-wedge polygons, and the basin progressively developed into a thermokarst lake. Interestingly, this happened in the middle of the Neoglacial cooling period, likely under colder-than-present but wetter-than-average conditions. Thereafter, the lake continued to develop as evidenced by the dominance of aquatic (both benthic and planktonic) diatom taxa ... Article in Journal/Newspaper Arctic Bylot Island Ice Nunavut permafrost The Cryosphere Thermokarst wedge* Alaska Siberia Université de Nantes: HAL-UNIV-NANTES Arctic Bylot Island Nunavut The Cryosphere 14 8 2607 2627 |
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Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Bouchard, Frédéric Fortier, Daniel Paquette, Michel Boucher, Vincent Pienitz, Reinhard Laurion, Isabelle Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Thermokarst lakes are widespread and diverse across permafrost regions, and they are considered significant contributors to global greenhouse gas emissions. Paleoenvironmental reconstructions documenting the inception and development of these ecologically important water bodies are generally limited to Pleistocene-age permafrost deposits of Siberia, Alaska, and the western Canadian Arctic. Here we present the gradual transition from syngenetic ice-wedge polygon terrain to a thermokarst lake in Holocene sediments of the eastern Canadian Arctic. We combine geomorphological surveys with paleolimnological reconstructions from sediment cores in an effort to characterize local landscape evolution from a terrestrial to freshwater environment. Located on an ice- and organic-rich polygonal terrace, the studied lake is now evolving through active thermokarst, as revealed by subsiding and eroding shores, and was likely created by water pooling within a pre-existing topographic depression. Organic sedimentation in the valley started during the mid-Holocene, as documented by the oldest organic debris found at the base of one sediment core and dated at 4.8 kyr BP. Local sedimentation dynamics were initially controlled by fluctuations in wind activity, local moisture, and vegetation growth and accumulation, as shown by alternating loess (silt) and peat layers. Fossil diatom assemblages were likewise influenced by local hydro-climatic conditions and reflect a broad range of substrates available in the past (both terrestrial and aquatic). Such conditions likely prevailed until ∼2000 BP, when peat accumulation stopped as water ponded the surface of degrading ice-wedge polygons, and the basin progressively developed into a thermokarst lake. Interestingly, this happened in the middle of the Neoglacial cooling period, likely under colder-than-present but wetter-than-average conditions. Thereafter, the lake continued to develop as evidenced by the dominance of aquatic (both benthic and planktonic) diatom taxa ... |
author2 |
Géosciences Paris Saclay (GEOPS) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Bouchard, Frédéric Fortier, Daniel Paquette, Michel Boucher, Vincent Pienitz, Reinhard Laurion, Isabelle |
author_facet |
Bouchard, Frédéric Fortier, Daniel Paquette, Michel Boucher, Vincent Pienitz, Reinhard Laurion, Isabelle |
author_sort |
Bouchard, Frédéric |
title |
Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic |
title_short |
Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic |
title_full |
Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic |
title_fullStr |
Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic |
title_full_unstemmed |
Thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, Bylot Island (Nunavut), eastern Canadian Arctic |
title_sort |
thermokarst lake inception and development in syngenetic ice-wedge polygon terrain during a cooling climatic trend, bylot island (nunavut), eastern canadian arctic |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal-insu.archives-ouvertes.fr/insu-03745266 https://hal-insu.archives-ouvertes.fr/insu-03745266/document https://hal-insu.archives-ouvertes.fr/insu-03745266/file/tc-14-2607-2020.pdf https://doi.org/10.5194/tc-14-2607-2020 |
geographic |
Arctic Bylot Island Nunavut |
geographic_facet |
Arctic Bylot Island Nunavut |
genre |
Arctic Bylot Island Ice Nunavut permafrost The Cryosphere Thermokarst wedge* Alaska Siberia |
genre_facet |
Arctic Bylot Island Ice Nunavut permafrost The Cryosphere Thermokarst wedge* Alaska Siberia |
op_source |
The Cryosphere https://hal-insu.archives-ouvertes.fr/insu-03745266 The Cryosphere, 2020, 14, pp.2607-2627. ⟨10.5194/tc-14-2607-2020⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-14-2607-2020 insu-03745266 https://hal-insu.archives-ouvertes.fr/insu-03745266 https://hal-insu.archives-ouvertes.fr/insu-03745266/document https://hal-insu.archives-ouvertes.fr/insu-03745266/file/tc-14-2607-2020.pdf BIBCODE: 2020TCry.14.2607B doi:10.5194/tc-14-2607-2020 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/tc-14-2607-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
8 |
container_start_page |
2607 |
op_container_end_page |
2627 |
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1766328665197510656 |