Pore fluids and the LGM ocean salinity—Reconsidered
Pore fluid chlorinity/salinity data from deep-sea cores related to the salinity maximum of the last glacial maximum (LGM) are analyzed using estimation methods deriving from linear control theory. With conventional diffusion coefficient values and no vertical advection, results show a very strong de...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Elsevier
2018
|
| Online Access: | http://hdl.handle.net/1721.1/114250 https://orcid.org/0000-0001-6808-3664 |
| _version_ | 1826195813583290368 |
|---|---|
| author | Wunsch, Carl Isaac |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Wunsch, Carl Isaac |
| author_sort | Wunsch, Carl Isaac |
| collection | MIT |
| description | Pore fluid chlorinity/salinity data from deep-sea cores related to the salinity maximum of the last glacial maximum (LGM) are analyzed using estimation methods deriving from linear control theory. With conventional diffusion coefficient values and no vertical advection, results show a very strong dependence upon initial conditions at −100 ky. Earlier inferences that the abyssal Southern Ocean was strongly salt-stratified in the LGM with a relatively fresh North Atlantic Ocean are found to be consistent within uncertainties of the salinity determination, which remain of order ±1 g/kg. However, an LGM Southern Ocean abyss with an important relative excess of salt is an assumption, one not required by existing core data. None of the present results show statistically significant abyssal salinity values above the global average, and results remain consistent, apart from a general increase owing to diminished sea level, with a more conventional salinity distribution having deep values lower than the global mean. The Southern Ocean core does show a higher salinity than the North Atlantic one on the Bermuda Rise at different water depths. Although much more sophisticated models of the pore-fluid salinity can be used, they will only increase the resulting uncertainties, unless considerably more data can be obtained. Results are consistent with complex regional variations in abyssal salinity during deglaciation, but none are statistically significant. Keywords: Last glacial maximum; Ocean salinity; Pore waters; Abyssal ocean |
| first_indexed | 2024-09-23T10:15:53Z |
| format | Article |
| id | mit-1721.1/114250 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:15:53Z |
| publishDate | 2018 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | mit-1721.1/1142502022-09-26T16:52:22Z Pore fluids and the LGM ocean salinity—Reconsidered Wunsch, Carl Isaac Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Wunsch, Carl Isaac Wunsch, Carl Isaac Pore fluid chlorinity/salinity data from deep-sea cores related to the salinity maximum of the last glacial maximum (LGM) are analyzed using estimation methods deriving from linear control theory. With conventional diffusion coefficient values and no vertical advection, results show a very strong dependence upon initial conditions at −100 ky. Earlier inferences that the abyssal Southern Ocean was strongly salt-stratified in the LGM with a relatively fresh North Atlantic Ocean are found to be consistent within uncertainties of the salinity determination, which remain of order ±1 g/kg. However, an LGM Southern Ocean abyss with an important relative excess of salt is an assumption, one not required by existing core data. None of the present results show statistically significant abyssal salinity values above the global average, and results remain consistent, apart from a general increase owing to diminished sea level, with a more conventional salinity distribution having deep values lower than the global mean. The Southern Ocean core does show a higher salinity than the North Atlantic one on the Bermuda Rise at different water depths. Although much more sophisticated models of the pore-fluid salinity can be used, they will only increase the resulting uncertainties, unless considerably more data can be obtained. Results are consistent with complex regional variations in abyssal salinity during deglaciation, but none are statistically significant. Keywords: Last glacial maximum; Ocean salinity; Pore waters; Abyssal ocean National Science Foundation (U.S.) (Grant OCE096713) 2018-03-21T18:07:06Z 2018-03-21T18:07:06Z 2016-02 2015-12 Article http://purl.org/eprint/type/JournalArticle 0277-3791 http://hdl.handle.net/1721.1/114250 Wunsch, Carl. "Pore fluids and the LGM ocean salinity—Reconsidered." Quaternary Science Reviews 135 (March 2016): 154-170 © 2016 Elsevier Ltd https://orcid.org/0000-0001-6808-3664 en_US http://dx.doi.org/10.1016/j.quascirev.2016.01.015 Quaternary Science Reviews Creative Commons Attribution-NonCommercial-NoDerivs License http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier Prof. Wunsch |
| spellingShingle | Wunsch, Carl Isaac Pore fluids and the LGM ocean salinity—Reconsidered |
| title | Pore fluids and the LGM ocean salinity—Reconsidered |
| title_full | Pore fluids and the LGM ocean salinity—Reconsidered |
| title_fullStr | Pore fluids and the LGM ocean salinity—Reconsidered |
| title_full_unstemmed | Pore fluids and the LGM ocean salinity—Reconsidered |
| title_short | Pore fluids and the LGM ocean salinity—Reconsidered |
| title_sort | pore fluids and the lgm ocean salinity reconsidered |
| url | http://hdl.handle.net/1721.1/114250 https://orcid.org/0000-0001-6808-3664 |
| work_keys_str_mv | AT wunschcarlisaac porefluidsandthelgmoceansalinityreconsidered |