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Rapid seafloor changes associated with the degradation of Arctic submarine permafrost

Repeated high-resolution bathymetric surveys of the shelf edge of the Canadian Beaufort Sea during 2- to 9-y-long survey intervals reveal rapid morphological changes. New steep-sided depressions up to 28 m in depth developed, and lateral retreat along scarp faces occurred at multiple sites. These mo...

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Autores principales: Paull, Charles K., Dallimore, Scott R., Jin, Young Keun, Caress, David W., Lundsten, Eve, Gwiazda, Roberto, Anderson, Krystle, Hughes Clarke, John, Youngblut, Scott, Melling, Humfrey
Formato: Online Artículo Texto
Lenguaje:English
Publicado: National Academy of Sciences 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8944826/
https://www.ncbi.nlm.nih.gov/pubmed/35286188
http://dx.doi.org/10.1073/pnas.2119105119
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author Paull, Charles K.
Dallimore, Scott R.
Jin, Young Keun
Caress, David W.
Lundsten, Eve
Gwiazda, Roberto
Anderson, Krystle
Hughes Clarke, John
Youngblut, Scott
Melling, Humfrey
author_facet Paull, Charles K.
Dallimore, Scott R.
Jin, Young Keun
Caress, David W.
Lundsten, Eve
Gwiazda, Roberto
Anderson, Krystle
Hughes Clarke, John
Youngblut, Scott
Melling, Humfrey
author_sort Paull, Charles K.
collection PubMed
description Repeated high-resolution bathymetric surveys of the shelf edge of the Canadian Beaufort Sea during 2- to 9-y-long survey intervals reveal rapid morphological changes. New steep-sided depressions up to 28 m in depth developed, and lateral retreat along scarp faces occurred at multiple sites. These morphological changes appeared between 120-m and 150-m water depth, near the maximum limit of the submerged glacial-age permafrost, and are attributed to permafrost thawing where ascending groundwater is concentrated along the relict permafrost boundary. The groundwater is produced by the regional thawing of the permafrost base due to the shift in the geothermal gradient as a result of the interglacial transgression of the shelf. In contrast, where groundwater discharge is reduced, sediments freeze at the ambient sea bottom temperature of ∼−1.4 °C. The consequent expansion of freezing sediment creates ice-cored topographic highs or pingos, which are particularly abundant adjacent to the discharge area.
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spelling pubmed-89448262022-03-25 Rapid seafloor changes associated with the degradation of Arctic submarine permafrost Paull, Charles K. Dallimore, Scott R. Jin, Young Keun Caress, David W. Lundsten, Eve Gwiazda, Roberto Anderson, Krystle Hughes Clarke, John Youngblut, Scott Melling, Humfrey Proc Natl Acad Sci U S A Physical Sciences Repeated high-resolution bathymetric surveys of the shelf edge of the Canadian Beaufort Sea during 2- to 9-y-long survey intervals reveal rapid morphological changes. New steep-sided depressions up to 28 m in depth developed, and lateral retreat along scarp faces occurred at multiple sites. These morphological changes appeared between 120-m and 150-m water depth, near the maximum limit of the submerged glacial-age permafrost, and are attributed to permafrost thawing where ascending groundwater is concentrated along the relict permafrost boundary. The groundwater is produced by the regional thawing of the permafrost base due to the shift in the geothermal gradient as a result of the interglacial transgression of the shelf. In contrast, where groundwater discharge is reduced, sediments freeze at the ambient sea bottom temperature of ∼−1.4 °C. The consequent expansion of freezing sediment creates ice-cored topographic highs or pingos, which are particularly abundant adjacent to the discharge area. National Academy of Sciences 2022-03-14 2022-03-22 /pmc/articles/PMC8944826/ /pubmed/35286188 http://dx.doi.org/10.1073/pnas.2119105119 Text en Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) .
spellingShingle Physical Sciences
Paull, Charles K.
Dallimore, Scott R.
Jin, Young Keun
Caress, David W.
Lundsten, Eve
Gwiazda, Roberto
Anderson, Krystle
Hughes Clarke, John
Youngblut, Scott
Melling, Humfrey
Rapid seafloor changes associated with the degradation of Arctic submarine permafrost
title Rapid seafloor changes associated with the degradation of Arctic submarine permafrost
title_full Rapid seafloor changes associated with the degradation of Arctic submarine permafrost
title_fullStr Rapid seafloor changes associated with the degradation of Arctic submarine permafrost
title_full_unstemmed Rapid seafloor changes associated with the degradation of Arctic submarine permafrost
title_short Rapid seafloor changes associated with the degradation of Arctic submarine permafrost
title_sort rapid seafloor changes associated with the degradation of arctic submarine permafrost
topic Physical Sciences
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8944826/
https://www.ncbi.nlm.nih.gov/pubmed/35286188
http://dx.doi.org/10.1073/pnas.2119105119
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