Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition
Five offshore drill holes northeast of Richards Island reveal permafrost conditions, which are interpreted in terms of the sea-level and paleoenvironmental history of the Canadian Beaufort Shelf. The top of ice-bonded permafrost lies 76–88 m below the seabed within 12 km of the shore, 11 m below the...
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Canadian Science Publishing
1996
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Online Access: | http://dx.doi.org/10.1139/e96-006 http://www.nrcresearchpress.com/doi/pdf/10.1139/e96-006 |
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crcansciencepubl:10.1139/e96-006 2024-09-09T19:26:11+00:00 Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition Taylor, Alan E. Dallimore, Scott R. Outcalt, S. I. 1996 http://dx.doi.org/10.1139/e96-006 http://www.nrcresearchpress.com/doi/pdf/10.1139/e96-006 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 33, issue 1, page 52-61 ISSN 0008-4077 1480-3313 journal-article 1996 crcansciencepubl https://doi.org/10.1139/e96-006 2024-06-20T04:11:56Z Five offshore drill holes northeast of Richards Island reveal permafrost conditions, which are interpreted in terms of the sea-level and paleoenvironmental history of the Canadian Beaufort Shelf. The top of ice-bonded permafrost lies 76–88 m below the seabed within 12 km of the shore, 11 m below the seabed 20 km offshore, and at 60 m some 50 km offshore. The base of permafrost is 500 m to over 700 m deep. Temperature–depth gradients are negative or nearly isothermal, and permafrost is degrading. Geothermal modelling of the temperatures and permafrost observations indicates that the sites were subaerially exposed throughout most of the Wisconsinan, and during the early Holocene. Three sites 2–10 km from the present shoreline experienced inundation at 3.5–4.0 ka. These times support dates of marine transgression predicted by the sea-level curve, but the sites may have been occupied by thermokarst lakes prior to transgression. In contrast, the site 20 km offshore with shallow ice bonding was inundated about 0.4 ka; this area may have persisted as an island until recently. Shoals observed nearby may be analogues of this process, being outliers that are now being eroded below sea level. Marine transgression occurred about 6 ka some 50 km offshore. Article in Journal/Newspaper Arctic Ice permafrost Richards Island Thermokarst Canadian Science Publishing Arctic Beaufort Shelf ENVELOPE(-142.500,-142.500,70.000,70.000) Canada Canadian Journal of Earth Sciences 33 1 52 61 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Five offshore drill holes northeast of Richards Island reveal permafrost conditions, which are interpreted in terms of the sea-level and paleoenvironmental history of the Canadian Beaufort Shelf. The top of ice-bonded permafrost lies 76–88 m below the seabed within 12 km of the shore, 11 m below the seabed 20 km offshore, and at 60 m some 50 km offshore. The base of permafrost is 500 m to over 700 m deep. Temperature–depth gradients are negative or nearly isothermal, and permafrost is degrading. Geothermal modelling of the temperatures and permafrost observations indicates that the sites were subaerially exposed throughout most of the Wisconsinan, and during the early Holocene. Three sites 2–10 km from the present shoreline experienced inundation at 3.5–4.0 ka. These times support dates of marine transgression predicted by the sea-level curve, but the sites may have been occupied by thermokarst lakes prior to transgression. In contrast, the site 20 km offshore with shallow ice bonding was inundated about 0.4 ka; this area may have persisted as an island until recently. Shoals observed nearby may be analogues of this process, being outliers that are now being eroded below sea level. Marine transgression occurred about 6 ka some 50 km offshore. |
format |
Article in Journal/Newspaper |
author |
Taylor, Alan E. Dallimore, Scott R. Outcalt, S. I. |
spellingShingle |
Taylor, Alan E. Dallimore, Scott R. Outcalt, S. I. Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition |
author_facet |
Taylor, Alan E. Dallimore, Scott R. Outcalt, S. I. |
author_sort |
Taylor, Alan E. |
title |
Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition |
title_short |
Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition |
title_full |
Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition |
title_fullStr |
Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition |
title_full_unstemmed |
Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 1. The onshore–offshore transition |
title_sort |
late quaternary history of the mackenzie–beaufort region, arctic canada, from modelling of permafrost temperatures. 1. the onshore–offshore transition |
publisher |
Canadian Science Publishing |
publishDate |
1996 |
url |
http://dx.doi.org/10.1139/e96-006 http://www.nrcresearchpress.com/doi/pdf/10.1139/e96-006 |
long_lat |
ENVELOPE(-142.500,-142.500,70.000,70.000) |
geographic |
Arctic Beaufort Shelf Canada |
geographic_facet |
Arctic Beaufort Shelf Canada |
genre |
Arctic Ice permafrost Richards Island Thermokarst |
genre_facet |
Arctic Ice permafrost Richards Island Thermokarst |
op_source |
Canadian Journal of Earth Sciences volume 33, issue 1, page 52-61 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e96-006 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
33 |
container_issue |
1 |
container_start_page |
52 |
op_container_end_page |
61 |
_version_ |
1809895840425181184 |