Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut.
The varved sediment record from glacially-fed Lake Tuborg, Ellesmere Island, Nunavut, shows that only three large jökulhlaups have occurred there in the last millennium: 2003, 1993, and 1960. Detailed analyses of sediment microstructure and particle size, combined with in-situ hydrometeorological an...
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ftinrsquebec:oai:espace.inrs.ca:10762 2023-05-15T15:13:40+02:00 Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. Lewis, Ted Francus, Pierre Bradley, Raymond S. 2009 https://espace.inrs.ca/id/eprint/10762/ https://doi.org/10.1007/s10933-008-9240-4 unknown Lewis, Ted, Francus, Pierre et Bradley, Raymond S. (2009). Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. Journal of Paleolimnology , vol. 41 , nº 3. p. 491-506. DOI:10.1007/s10933-008-9240-4 <https://doi.org/10.1007/s10933-008-9240-4>. doi:10.1007/s10933-008-9240-4 jökulhlaup varve ice-dammed lake Canadian High Arctic lake processes Article Évalué par les pairs 2009 ftinrsquebec https://doi.org/10.1007/s10933-008-9240-4 2023-02-10T11:46:18Z The varved sediment record from glacially-fed Lake Tuborg, Ellesmere Island, Nunavut, shows that only three large jökulhlaups have occurred there in the last millennium: 2003, 1993, and 1960. Detailed analyses of sediment microstructure and particle size, combined with in-situ hydrometeorological and limnological process studies, allowed jökulhlaup facies identification and discrimination from deposits from other processes. Deposits from large jökulhlaups are anomalously thick, typically lack internal structure, have sharp bases, and fine upwards. The ice-dammed lake above Lake Tuborg (the source of the jökulhlaups) likely changed its drainage style in 1960, from ice-dam overtopping to ice-dam flotation and glacial tunnel enlargement by melt widening, which allowed the lake to drain completely and catastrophically. Complete drainage of ice-dammed lakes by ice-dam flotation is rare in the region is due to the pervasiveness of cold-based ice. Twentieth century warming is likely responsible for some combination of dam thinning, lake expansion and deepening, and changing the thermal regime at the base of the dam. Anomalously thick individual varves were periodically deposited beginning in the nineteenth century, and their thickness increased with time. This likely reflects a combination of increased ice dam overtopping, subaqueous slope failures, sediment availability and rising air temperature. The varve record presented here significantly correlates with a previous, shorter record from Lake Tuborg. However, generally weak correlations are found between the new varve time series, regional records of air temperature, and glacial melt from ice cores on the Agassiz Ice Cap. It is hypothesized that on short timescales, sedimentation at the coring location reflects a complex and varying integration of multiple hydroclimatic, geomorphic and limnologic influences. Article in Journal/Newspaper Arctic Ellesmere Island Ice cap Nunavut Institut national de la recherche scientifique, Québec: Espace INRS Agassiz Ice Cap ENVELOPE(-75.996,-75.996,80.252,80.252) Arctic Arctic Lake ENVELOPE(-130.826,-130.826,57.231,57.231) Dammed Lake ENVELOPE(-68.258,-68.258,68.496,68.496) Ellesmere Island Lake Tuborg ENVELOPE(-75.583,-75.583,80.950,80.950) Nunavut Journal of Paleolimnology 41 3 491 506 |
institution |
Open Polar |
collection |
Institut national de la recherche scientifique, Québec: Espace INRS |
op_collection_id |
ftinrsquebec |
language |
unknown |
topic |
jökulhlaup varve ice-dammed lake Canadian High Arctic lake processes |
spellingShingle |
jökulhlaup varve ice-dammed lake Canadian High Arctic lake processes Lewis, Ted Francus, Pierre Bradley, Raymond S. Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. |
topic_facet |
jökulhlaup varve ice-dammed lake Canadian High Arctic lake processes |
description |
The varved sediment record from glacially-fed Lake Tuborg, Ellesmere Island, Nunavut, shows that only three large jökulhlaups have occurred there in the last millennium: 2003, 1993, and 1960. Detailed analyses of sediment microstructure and particle size, combined with in-situ hydrometeorological and limnological process studies, allowed jökulhlaup facies identification and discrimination from deposits from other processes. Deposits from large jökulhlaups are anomalously thick, typically lack internal structure, have sharp bases, and fine upwards. The ice-dammed lake above Lake Tuborg (the source of the jökulhlaups) likely changed its drainage style in 1960, from ice-dam overtopping to ice-dam flotation and glacial tunnel enlargement by melt widening, which allowed the lake to drain completely and catastrophically. Complete drainage of ice-dammed lakes by ice-dam flotation is rare in the region is due to the pervasiveness of cold-based ice. Twentieth century warming is likely responsible for some combination of dam thinning, lake expansion and deepening, and changing the thermal regime at the base of the dam. Anomalously thick individual varves were periodically deposited beginning in the nineteenth century, and their thickness increased with time. This likely reflects a combination of increased ice dam overtopping, subaqueous slope failures, sediment availability and rising air temperature. The varve record presented here significantly correlates with a previous, shorter record from Lake Tuborg. However, generally weak correlations are found between the new varve time series, regional records of air temperature, and glacial melt from ice cores on the Agassiz Ice Cap. It is hypothesized that on short timescales, sedimentation at the coring location reflects a complex and varying integration of multiple hydroclimatic, geomorphic and limnologic influences. |
format |
Article in Journal/Newspaper |
author |
Lewis, Ted Francus, Pierre Bradley, Raymond S. |
author_facet |
Lewis, Ted Francus, Pierre Bradley, Raymond S. |
author_sort |
Lewis, Ted |
title |
Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. |
title_short |
Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. |
title_full |
Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. |
title_fullStr |
Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. |
title_full_unstemmed |
Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. |
title_sort |
recent occurrence of large jökulhlaups at lake tuborg, ellesmere island, nunavut. |
publishDate |
2009 |
url |
https://espace.inrs.ca/id/eprint/10762/ https://doi.org/10.1007/s10933-008-9240-4 |
long_lat |
ENVELOPE(-75.996,-75.996,80.252,80.252) ENVELOPE(-130.826,-130.826,57.231,57.231) ENVELOPE(-68.258,-68.258,68.496,68.496) ENVELOPE(-75.583,-75.583,80.950,80.950) |
geographic |
Agassiz Ice Cap Arctic Arctic Lake Dammed Lake Ellesmere Island Lake Tuborg Nunavut |
geographic_facet |
Agassiz Ice Cap Arctic Arctic Lake Dammed Lake Ellesmere Island Lake Tuborg Nunavut |
genre |
Arctic Ellesmere Island Ice cap Nunavut |
genre_facet |
Arctic Ellesmere Island Ice cap Nunavut |
op_relation |
Lewis, Ted, Francus, Pierre et Bradley, Raymond S. (2009). Recent occurrence of large jökulhlaups at Lake Tuborg, Ellesmere Island, Nunavut. Journal of Paleolimnology , vol. 41 , nº 3. p. 491-506. DOI:10.1007/s10933-008-9240-4 <https://doi.org/10.1007/s10933-008-9240-4>. doi:10.1007/s10933-008-9240-4 |
op_doi |
https://doi.org/10.1007/s10933-008-9240-4 |
container_title |
Journal of Paleolimnology |
container_volume |
41 |
container_issue |
3 |
container_start_page |
491 |
op_container_end_page |
506 |
_version_ |
1766344201550692352 |