Mechanism for the subglacial formation of cryogenic brines
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...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2022-09-01
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| Series: | Annals of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0260305523000289/type/journal_article |
| _version_ | 1797660603360215040 |
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| author | Sarah U. Neuhaus Slawek M. Tulaczyk |
| author_facet | Sarah U. Neuhaus Slawek M. Tulaczyk |
| author_sort | Sarah U. Neuhaus |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-11T18:32:17Z |
| format | Article |
| id | doaj.art-c33b1fd812914990b01c598310f55f6e |
| institution | Directory Open Access Journal |
| issn | 0260-3055 1727-5644 |
| language | English |
| last_indexed | 2024-03-11T18:32:17Z |
| publishDate | 2022-09-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Annals of Glaciology |
| spelling | doaj.art-c33b1fd812914990b01c598310f55f6e2023-10-13T10:44:52ZengCambridge University PressAnnals of Glaciology0260-30551727-56442022-09-016312112410.1017/aog.2023.28Mechanism for the subglacial formation of cryogenic brinesSarah U. Neuhaus0Slawek M. Tulaczyk1https://orcid.org/0000-0002-9711-4332Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USAEarth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USACryogenic 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.https://www.cambridge.org/core/product/identifier/S0260305523000289/type/journal_articleGlacier hydrochemistryice/ocean interactionsmeltwater chemistry |
| spellingShingle | Sarah U. Neuhaus Slawek M. Tulaczyk Mechanism for the subglacial formation of cryogenic brines Annals of Glaciology Glacier hydrochemistry ice/ocean interactions meltwater chemistry |
| title | 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_short | Mechanism for the subglacial formation of cryogenic brines |
| title_sort | mechanism for the subglacial formation of cryogenic brines |
| topic | Glacier hydrochemistry ice/ocean interactions meltwater chemistry |
| url | https://www.cambridge.org/core/product/identifier/S0260305523000289/type/journal_article |
| work_keys_str_mv | AT sarahuneuhaus mechanismforthesubglacialformationofcryogenicbrines AT slawekmtulaczyk mechanismforthesubglacialformationofcryogenicbrines |