A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments
Permafrost degradation associated with the expansion of thermokarst lakes is commonly interrupted by catastrophic drainage. Subsequently, in tundra areas, permafrost aggradation in drained basins leads to uneven topography characterized by raised centres and wet, depressed margins. The genesis of su...
Published in: | Earth Surface Processes and Landforms |
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Language: | English |
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Online Access: | https://ir.library.carleton.ca/pub/9263 https://doi.org/10.1002/esp.3918 |
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ftcarletonunivir:oai:carleton.ca:9263 2023-05-15T16:36:49+02:00 A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments Roy-Léveillée, P. (Pascale) Burn, C. (Christopher R.) 2016-01-01 https://ir.library.carleton.ca/pub/9263 https://doi.org/10.1002/esp.3918 en eng https://ir.library.carleton.ca/pub/9263 doi:10.1002/esp.3918 Earth Surface Processes and Landforms Lacustrine sediment Lake basins Permafrost Thermokarst info:eu-repo/semantics/article 2016 ftcarletonunivir https://doi.org/10.1002/esp.3918 2022-02-06T21:51:16Z Permafrost degradation associated with the expansion of thermokarst lakes is commonly interrupted by catastrophic drainage. Subsequently, in tundra areas, permafrost aggradation in drained basins leads to uneven topography characterized by raised centres and wet, depressed margins. The genesis of such topography has been investigated in Old Crow Flats (OCF), a glaciolacustrine plain in the continuous permafrost of northern Yukon. The thermokarst lakes of OCF have a mean depth of only 1.5 m because excess ice is dominantly found only in the uppermost 10 m of the ground. Surface conditions were measured in three drained thermokarst lake basins, including relief, snow conditions, ground temperatures, near-surface ground ice, and sediment stratigraphy. Four nearby lakes provided information on wave base, shore recession patterns, and bathymetry before drainage: the bottoms of these lakes were not raised in the centre. An elevation difference of up to 2 m was recorded between drained basin margins and centres but was not associated with variations in ice-wedge density or segregated ice content. Hence basin topography was not controlled by differences in volumetric ground-ice content between margins and centres. We propose that transport of fine sediment away from eroding lake margins during lake development is the primary mechanism for the genesis of depressed margins and raised centres in drained basins of OCF. Over time, the transport results in the deposition of more and finer sediment in the central parts of lakes, where the lake bottom has subsided below wave base, than at the shallow margins, where resuspension by wave action occurs frequently. This difference in sediment volume is revealed in the topography after drainage, when permafrost aggrades in the lake-bottom sediment and underlying talik. Article in Journal/Newspaper Ice Old Crow permafrost Thermokarst Tundra wedge* Yukon Carleton University's Institutional Repository Old Crow Flats ENVELOPE(-139.755,-139.755,68.083,68.083) Talik ENVELOPE(146.601,146.601,59.667,59.667) Yukon Earth Surface Processes and Landforms 41 11 1504 1520 |
institution |
Open Polar |
collection |
Carleton University's Institutional Repository |
op_collection_id |
ftcarletonunivir |
language |
English |
topic |
Lacustrine sediment Lake basins Permafrost Thermokarst |
spellingShingle |
Lacustrine sediment Lake basins Permafrost Thermokarst Roy-Léveillée, P. (Pascale) Burn, C. (Christopher R.) A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
topic_facet |
Lacustrine sediment Lake basins Permafrost Thermokarst |
description |
Permafrost degradation associated with the expansion of thermokarst lakes is commonly interrupted by catastrophic drainage. Subsequently, in tundra areas, permafrost aggradation in drained basins leads to uneven topography characterized by raised centres and wet, depressed margins. The genesis of such topography has been investigated in Old Crow Flats (OCF), a glaciolacustrine plain in the continuous permafrost of northern Yukon. The thermokarst lakes of OCF have a mean depth of only 1.5 m because excess ice is dominantly found only in the uppermost 10 m of the ground. Surface conditions were measured in three drained thermokarst lake basins, including relief, snow conditions, ground temperatures, near-surface ground ice, and sediment stratigraphy. Four nearby lakes provided information on wave base, shore recession patterns, and bathymetry before drainage: the bottoms of these lakes were not raised in the centre. An elevation difference of up to 2 m was recorded between drained basin margins and centres but was not associated with variations in ice-wedge density or segregated ice content. Hence basin topography was not controlled by differences in volumetric ground-ice content between margins and centres. We propose that transport of fine sediment away from eroding lake margins during lake development is the primary mechanism for the genesis of depressed margins and raised centres in drained basins of OCF. Over time, the transport results in the deposition of more and finer sediment in the central parts of lakes, where the lake bottom has subsided below wave base, than at the shallow margins, where resuspension by wave action occurs frequently. This difference in sediment volume is revealed in the topography after drainage, when permafrost aggrades in the lake-bottom sediment and underlying talik. |
format |
Article in Journal/Newspaper |
author |
Roy-Léveillée, P. (Pascale) Burn, C. (Christopher R.) |
author_facet |
Roy-Léveillée, P. (Pascale) Burn, C. (Christopher R.) |
author_sort |
Roy-Léveillée, P. (Pascale) |
title |
A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
title_short |
A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
title_full |
A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
title_fullStr |
A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
title_full_unstemmed |
A modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
title_sort |
modified landform development model for the topography of drained thermokarst lake basins in fine-grained sediments |
publishDate |
2016 |
url |
https://ir.library.carleton.ca/pub/9263 https://doi.org/10.1002/esp.3918 |
long_lat |
ENVELOPE(-139.755,-139.755,68.083,68.083) ENVELOPE(146.601,146.601,59.667,59.667) |
geographic |
Old Crow Flats Talik Yukon |
geographic_facet |
Old Crow Flats Talik Yukon |
genre |
Ice Old Crow permafrost Thermokarst Tundra wedge* Yukon |
genre_facet |
Ice Old Crow permafrost Thermokarst Tundra wedge* Yukon |
op_source |
Earth Surface Processes and Landforms |
op_relation |
https://ir.library.carleton.ca/pub/9263 doi:10.1002/esp.3918 |
op_doi |
https://doi.org/10.1002/esp.3918 |
container_title |
Earth Surface Processes and Landforms |
container_volume |
41 |
container_issue |
11 |
container_start_page |
1504 |
op_container_end_page |
1520 |
_version_ |
1766027138247426048 |