Mechanism for the subglacial formation of cryogenic brines
Abstract Cryogenic brines are under-studied, despite the fact that they may contain information about past ice-sheet behavior. Cryogenic brines form through cryoconcentration of seawater, although the specific setting and mechanism of formation have been debated. Previous conceptual models of brine...
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2022
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Online Access: | http://dx.doi.org/10.1017/aog.2023.28 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305523000289 |
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crcambridgeupr:10.1017/aog.2023.28 2024-06-09T07:38:33+00:00 Mechanism for the subglacial formation of cryogenic brines Neuhaus, Sarah U. Tulaczyk, Slawek M. National Science Foundation National Science Foundation 2022 http://dx.doi.org/10.1017/aog.2023.28 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305523000289 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Annals of Glaciology volume 63, issue 87-89, page 121-124 ISSN 0260-3055 1727-5644 journal-article 2022 crcambridgeupr https://doi.org/10.1017/aog.2023.28 2024-05-15T12:59:10Z Abstract Cryogenic brines are under-studied, despite the fact that they may contain information about past ice-sheet behavior. Cryogenic brines form through cryoconcentration of seawater, although the specific setting and mechanism of formation have been debated. Previous conceptual models of brine formation require seawater isolation from the ocean in a closed basin experiencing freezing. We propose instead that they may form in pore spaces of marine sediments subjected to repeat cycles of ice-sheet advance and retreat. During periods of basal freezing, cryoconcentration produces hypersaline brines which experience downward flow driven by unstable density stratification. Our advection-diffusion model of porewater chemistry evolution successfully recreates the porewater chemistry of two deep Antarctic cores containing cryogenic brines (AND-1B and AND-2A), suggesting that cryogenic brines can be formed through the repeated isolation and cryoconcentration of marine waters within subglacial sediment pore spaces of modern and past ice sheets. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctic Ice Sheet Cambridge University Press Antarctic Annals of Glaciology 63 87-89 121 124 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract Cryogenic brines are under-studied, despite the fact that they may contain information about past ice-sheet behavior. Cryogenic brines form through cryoconcentration of seawater, although the specific setting and mechanism of formation have been debated. Previous conceptual models of brine formation require seawater isolation from the ocean in a closed basin experiencing freezing. We propose instead that they may form in pore spaces of marine sediments subjected to repeat cycles of ice-sheet advance and retreat. During periods of basal freezing, cryoconcentration produces hypersaline brines which experience downward flow driven by unstable density stratification. Our advection-diffusion model of porewater chemistry evolution successfully recreates the porewater chemistry of two deep Antarctic cores containing cryogenic brines (AND-1B and AND-2A), suggesting that cryogenic brines can be formed through the repeated isolation and cryoconcentration of marine waters within subglacial sediment pore spaces of modern and past ice sheets. |
author2 |
National Science Foundation National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Neuhaus, Sarah U. Tulaczyk, Slawek M. |
spellingShingle |
Neuhaus, Sarah U. Tulaczyk, Slawek M. Mechanism for the subglacial formation of cryogenic brines |
author_facet |
Neuhaus, Sarah U. Tulaczyk, Slawek M. |
author_sort |
Neuhaus, Sarah U. |
title |
Mechanism for the subglacial formation of cryogenic brines |
title_short |
Mechanism for the subglacial formation of cryogenic brines |
title_full |
Mechanism for the subglacial formation of cryogenic brines |
title_fullStr |
Mechanism for the subglacial formation of cryogenic brines |
title_full_unstemmed |
Mechanism for the subglacial formation of cryogenic brines |
title_sort |
mechanism for the subglacial formation of cryogenic brines |
publisher |
Cambridge University Press (CUP) |
publishDate |
2022 |
url |
http://dx.doi.org/10.1017/aog.2023.28 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305523000289 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Annals of Glaciology Antarc* Antarctic Ice Sheet |
genre_facet |
Annals of Glaciology Antarc* Antarctic Ice Sheet |
op_source |
Annals of Glaciology volume 63, issue 87-89, page 121-124 ISSN 0260-3055 1727-5644 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/aog.2023.28 |
container_title |
Annals of Glaciology |
container_volume |
63 |
container_issue |
87-89 |
container_start_page |
121 |
op_container_end_page |
124 |
_version_ |
1801373614739554304 |