A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years
The circulation of intermediate waters plays an important role in global heat and carbon transport in the ocean and changes in their distribution are closely tied to glacial–interglacial climate change. Coupled radiocarbon and U/Th measurements on deep-sea Desmophyllum dianthus corals allow for th...
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Online Access: | https://doi.org/10.1016/j.epsl.2015.09.038 |
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ftcaltechauth:oai:authors.library.caltech.edu:nt6eq-3bm66 2024-06-23T07:47:17+00:00 A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years Hines, Sophia K. V. Southon, John R. Adkins, Jess F. 2015-12-15 https://doi.org/10.1016/j.epsl.2015.09.038 unknown Elsevier https://doi.org/10.1016/j.epsl.2015.09.038 oai:authors.library.caltech.edu:nt6eq-3bm66 eprintid:61966 resolverid:CaltechAUTHORS:20151106-150028884 info:eu-repo/semantics/openAccess Other Earth and Planetary Science Letters, 432, 46-58, (2015-12-15) Southern Ocean radiocarbon glacial–interglacial climate change meridional overturning circulation Southern Ocean fronts intermediate water info:eu-repo/semantics/article 2015 ftcaltechauth https://doi.org/10.1016/j.epsl.2015.09.038 2024-06-12T06:27:06Z The circulation of intermediate waters plays an important role in global heat and carbon transport in the ocean and changes in their distribution are closely tied to glacial–interglacial climate change. Coupled radiocarbon and U/Th measurements on deep-sea Desmophyllum dianthus corals allow for the reconstruction of past intermediate water ventilation. We present a high-resolution time series of Antarctic Intermediate Water radiocarbon from 44 corals spanning 30 ka through the start of the Holocene, encompassing the transition into the Last Glacial Maximum (LGM) and the last deglaciation. Corals were collected south of Tasmania from water depths between 1430 and 1950 m with 80% of them between 1500 and 1700 m, giving us a continuous record from a narrow depth range. The record shows three distinct periods of circulation: the MIS 3–2 transition, the LGM/Heinrich Stadial 1 (extending from ∼22 to 16 kyr BP), and the Antarctic Cold Reversal (ACR). The MIS 3–2 transition and the ACR are characterized by abrupt changes in intermediate water radiocarbon while the LGM time period generally follows the atmosphere at a constant offset, in support of the idea that the LGM ocean was at steady state for its ^(14)C distribution. Closer inspection of the LGM time period reveals a 40‰ jump at ∼19 ka from an atmospheric offset of roughly 230‰ to 190‰, coincident with an observed 10–15 m rise in sea level and a southward shift of the Subantarctic and Polar Fronts, an abrupt change not seen in deeper records. During the ACR time period intermediate water radiocarbon is on average less offset from the atmosphere (∼110‰∼110‰) and much more variable. This variability has been captured within the lifetimes of three individual corals with changes of up to 35‰ over ∼40 yr, likely caused by the movement of Southern Ocean fronts. This surprising result of relatively young and variable intermediate water radiocarbon during the ACR seems to go against the canonical idea of reduced circulation and ventilation in ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Caltech Authors (California Institute of Technology) Antarctic Southern Ocean The Antarctic Earth and Planetary Science Letters 432 46 58 |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
Southern Ocean radiocarbon glacial–interglacial climate change meridional overturning circulation Southern Ocean fronts intermediate water |
spellingShingle |
Southern Ocean radiocarbon glacial–interglacial climate change meridional overturning circulation Southern Ocean fronts intermediate water Hines, Sophia K. V. Southon, John R. Adkins, Jess F. A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years |
topic_facet |
Southern Ocean radiocarbon glacial–interglacial climate change meridional overturning circulation Southern Ocean fronts intermediate water |
description |
The circulation of intermediate waters plays an important role in global heat and carbon transport in the ocean and changes in their distribution are closely tied to glacial–interglacial climate change. Coupled radiocarbon and U/Th measurements on deep-sea Desmophyllum dianthus corals allow for the reconstruction of past intermediate water ventilation. We present a high-resolution time series of Antarctic Intermediate Water radiocarbon from 44 corals spanning 30 ka through the start of the Holocene, encompassing the transition into the Last Glacial Maximum (LGM) and the last deglaciation. Corals were collected south of Tasmania from water depths between 1430 and 1950 m with 80% of them between 1500 and 1700 m, giving us a continuous record from a narrow depth range. The record shows three distinct periods of circulation: the MIS 3–2 transition, the LGM/Heinrich Stadial 1 (extending from ∼22 to 16 kyr BP), and the Antarctic Cold Reversal (ACR). The MIS 3–2 transition and the ACR are characterized by abrupt changes in intermediate water radiocarbon while the LGM time period generally follows the atmosphere at a constant offset, in support of the idea that the LGM ocean was at steady state for its ^(14)C distribution. Closer inspection of the LGM time period reveals a 40‰ jump at ∼19 ka from an atmospheric offset of roughly 230‰ to 190‰, coincident with an observed 10–15 m rise in sea level and a southward shift of the Subantarctic and Polar Fronts, an abrupt change not seen in deeper records. During the ACR time period intermediate water radiocarbon is on average less offset from the atmosphere (∼110‰∼110‰) and much more variable. This variability has been captured within the lifetimes of three individual corals with changes of up to 35‰ over ∼40 yr, likely caused by the movement of Southern Ocean fronts. This surprising result of relatively young and variable intermediate water radiocarbon during the ACR seems to go against the canonical idea of reduced circulation and ventilation in ... |
format |
Article in Journal/Newspaper |
author |
Hines, Sophia K. V. Southon, John R. Adkins, Jess F. |
author_facet |
Hines, Sophia K. V. Southon, John R. Adkins, Jess F. |
author_sort |
Hines, Sophia K. V. |
title |
A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years |
title_short |
A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years |
title_full |
A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years |
title_fullStr |
A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years |
title_full_unstemmed |
A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years |
title_sort |
high-resolution record of southern ocean intermediate water radiocarbon over the past 30,000 years |
publisher |
Elsevier |
publishDate |
2015 |
url |
https://doi.org/10.1016/j.epsl.2015.09.038 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Earth and Planetary Science Letters, 432, 46-58, (2015-12-15) |
op_relation |
https://doi.org/10.1016/j.epsl.2015.09.038 oai:authors.library.caltech.edu:nt6eq-3bm66 eprintid:61966 resolverid:CaltechAUTHORS:20151106-150028884 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1016/j.epsl.2015.09.038 |
container_title |
Earth and Planetary Science Letters |
container_volume |
432 |
container_start_page |
46 |
op_container_end_page |
58 |
_version_ |
1802651376306618368 |