A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient
The fact that the deep-ocean benthic δ 13 C minimum shifted from the North Pacific to the South Atlantic during the Last Glacial Maximum is often interpretted as evidence of a change in deep water circulation, such as the development of deep water ventilation in the North Pacific or a decrease in So...
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ftcopernicus:oai:publications.copernicus.org:cp2491 2023-05-15T18:25:29+02:00 A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient Lisiecki, L. E. 2018-09-27 application/pdf https://doi.org/10.5194/cp-6-305-2010 https://cp.copernicus.org/articles/6/305/2010/ eng eng doi:10.5194/cp-6-305-2010 https://cp.copernicus.org/articles/6/305/2010/ eISSN: 1814-9332 Text 2018 ftcopernicus https://doi.org/10.5194/cp-6-305-2010 2020-07-20T16:26:25Z The fact that the deep-ocean benthic δ 13 C minimum shifted from the North Pacific to the South Atlantic during the Last Glacial Maximum is often interpretted as evidence of a change in deep water circulation, such as the development of deep water ventilation in the North Pacific or a decrease in Southern Ocean overturning. This study re-evaluates the implications of changes in benthic δ 13 C gradients by comparing Pacific Deep Water (PDW) δ 13 C measurements with the values expected for the null hypothesis that PDW ventilation sources remained unchanged throughout the Late Pleistocene. The δ 13 C compositions of PDW, Northern Component Water (NCW) and Southern Component Water (SCW) are estimated from regional benthic δ 13 C stacks of 3–6 sites. Changes in PDW δ 13 C and PDW-SCW δ 13 C gradients over the past 800 kyr are found to be well described by a constant mixture of 60% NCW and 40% SCW plus a constant Pacific remineralization offset of −0.5‰. Thus, a change in PDW ventilation cannot be inferred solely on the basis of changes in the Pacific-South Atlantic benthic δ 13 C gradient. Text Southern Ocean Copernicus Publications: E-Journals Pacific Southern Ocean Climate of the Past 6 3 305 314 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The fact that the deep-ocean benthic δ 13 C minimum shifted from the North Pacific to the South Atlantic during the Last Glacial Maximum is often interpretted as evidence of a change in deep water circulation, such as the development of deep water ventilation in the North Pacific or a decrease in Southern Ocean overturning. This study re-evaluates the implications of changes in benthic δ 13 C gradients by comparing Pacific Deep Water (PDW) δ 13 C measurements with the values expected for the null hypothesis that PDW ventilation sources remained unchanged throughout the Late Pleistocene. The δ 13 C compositions of PDW, Northern Component Water (NCW) and Southern Component Water (SCW) are estimated from regional benthic δ 13 C stacks of 3–6 sites. Changes in PDW δ 13 C and PDW-SCW δ 13 C gradients over the past 800 kyr are found to be well described by a constant mixture of 60% NCW and 40% SCW plus a constant Pacific remineralization offset of −0.5‰. Thus, a change in PDW ventilation cannot be inferred solely on the basis of changes in the Pacific-South Atlantic benthic δ 13 C gradient. |
format |
Text |
author |
Lisiecki, L. E. |
spellingShingle |
Lisiecki, L. E. A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient |
author_facet |
Lisiecki, L. E. |
author_sort |
Lisiecki, L. E. |
title |
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient |
title_short |
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient |
title_full |
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient |
title_fullStr |
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient |
title_full_unstemmed |
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient |
title_sort |
simple mixing explanation for late pleistocene changes in the pacific-south atlantic benthic δ13c gradient |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-6-305-2010 https://cp.copernicus.org/articles/6/305/2010/ |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-6-305-2010 https://cp.copernicus.org/articles/6/305/2010/ |
op_doi |
https://doi.org/10.5194/cp-6-305-2010 |
container_title |
Climate of the Past |
container_volume |
6 |
container_issue |
3 |
container_start_page |
305 |
op_container_end_page |
314 |
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1766206978145648640 |