Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios
An earlier analysis of pore-water salinity (chlorinity) in two deep-sea cores, using terminal constraint methods of control theory, concluded that although a salinity amplification in the abyss was possible during the LGM, it was not required by the data. Here the same methodology is applied to δ[su...
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| Format: | Article |
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Copernicus GmbH
2018
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| Online Access: | http://hdl.handle.net/1721.1/113851 https://orcid.org/0000-0001-6808-3664 |
| _version_ | 1826200702635999232 |
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| 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 | An earlier analysis of pore-water salinity (chlorinity) in two deep-sea cores, using terminal constraint methods of control theory, concluded that although a salinity amplification in the abyss was possible during the LGM, it was not required by the data. Here the same methodology is applied to δ[superscript 18]O[subscript w] in the upper 100 m of four deep-sea cores. An ice volume amplification to the isotopic ratio is, again, consistent with the data but not required by it. In particular, results are very sensitive, with conventional diffusion values, to the assumed initial conditions at −100 ky and a long list of noise (uncertainty) assumptions. If the calcite values of δ[superscript 18]O are fully reliable, then published enriched values of the ratio in seawater are necessary to preclude sub-freezing temperatures, but the seawater δ[superscript 18]O in pore fluids does not independently require the conclusion. |
| first_indexed | 2024-09-23T11:40:31Z |
| format | Article |
| id | mit-1721.1/113851 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T11:40:31Z |
| publishDate | 2018 |
| publisher | Copernicus GmbH |
| record_format | dspace |
| spelling | mit-1721.1/1138512022-09-27T21:10:07Z Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios Wunsch, Carl Isaac Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Wunsch, Carl Isaac An earlier analysis of pore-water salinity (chlorinity) in two deep-sea cores, using terminal constraint methods of control theory, concluded that although a salinity amplification in the abyss was possible during the LGM, it was not required by the data. Here the same methodology is applied to δ[superscript 18]O[subscript w] in the upper 100 m of four deep-sea cores. An ice volume amplification to the isotopic ratio is, again, consistent with the data but not required by it. In particular, results are very sensitive, with conventional diffusion values, to the assumed initial conditions at −100 ky and a long list of noise (uncertainty) assumptions. If the calcite values of δ[superscript 18]O are fully reliable, then published enriched values of the ratio in seawater are necessary to preclude sub-freezing temperatures, but the seawater δ[superscript 18]O in pore fluids does not independently require the conclusion. National Science Foundation (U.S.) (Grant OCE09671) 2018-02-21T16:43:38Z 2018-02-21T16:43:38Z 2016-06 2016-05 2018-02-16T18:30:57Z Article http://purl.org/eprint/type/JournalArticle 1814-9332 http://hdl.handle.net/1721.1/113851 Wunsch, Carl. “Last Glacial Maximum and Deglacial Abyssal Seawater Oxygen Isotopic Ratios.” Climate of the Past 12, 6 (June 2016): 1281–1296 https://orcid.org/0000-0001-6808-3664 http://dx.doi.org/10.5194/CP-12-1281-2016 Climate of the Past Attribution 3.0 Unported (CC BY 3.0) https://creativecommons.org/licenses/by/3.0/ application/pdf Copernicus GmbH Copernicus Publications |
| spellingShingle | Wunsch, Carl Isaac Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios |
| title | Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios |
| title_full | Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios |
| title_fullStr | Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios |
| title_full_unstemmed | Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios |
| title_short | Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios |
| title_sort | last glacial maximum and deglacial abyssal seawater oxygen isotopic ratios |
| url | http://hdl.handle.net/1721.1/113851 https://orcid.org/0000-0001-6808-3664 |
| work_keys_str_mv | AT wunschcarlisaac lastglacialmaximumanddeglacialabyssalseawateroxygenisotopicratios |