Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin
Reconstruction of the Mediterranean Outflow Water (MOW) dynamics in the geologic past contributes to exploring its influence on the North Atlantic Ocean circulation and global climate. The middle Pleistocene transition (MPT) is one of the most important characteristics of Quaternary climate change,...
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ftunivalgarve:oai:sapientia.ualg.pt:10400.1/16352 2023-05-15T17:37:08+02:00 Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin Guo, Qimei Li, Baohua Voelker, Antje Kim, Jin-Kyoung 2020-11 http://hdl.handle.net/10400.1/16352 https://doi.org/10.1016/j.quascirev.2020.106567 eng eng Elsevier info:eu-repo/grantAgreement/EC/FP7/228344/EU 0277-3791 http://hdl.handle.net/10400.1/16352 doi:10.1016/j.quascirev.2020.106567 restrictedAccess Benthic foraminifera Stable oxygen and carbon isotopes Middle pleistocene transition Mediterranean outflow water Bottom water ventilation Physical geography article 2020 ftunivalgarve https://doi.org/10.1016/j.quascirev.2020.106567 2022-05-30T08:49:52Z Reconstruction of the Mediterranean Outflow Water (MOW) dynamics in the geologic past contributes to exploring its influence on the North Atlantic Ocean circulation and global climate. The middle Pleistocene transition (MPT) is one of the most important characteristics of Quaternary climate change, but until now, research on the MOW variability during this time interval has been limited. To decipher the MOW variability over the last 1.3 myr, this work presents the first continuous and high-resolution (similar to 2 kyr) foraminiferal stable oxygen and carbon isotopes and benthic foraminiferal records from Integrated Ocean Drilling Program (IODP) Site U1391, which was drilled off the Portuguese margin in the Northeast Atlantic Ocean and is currently bathed by the lower MOW core. Based on spectral analysis results of the foraminiferal delta O-18 record, the MPT peaked from 0.9 to 0.7 Ma. The 'epibenthos group' was previously found attached to elevated substrates only within the MOW current and more abundant at higher current velocities, so the relative abundance of the 'elevated epibenthos group' was adopted as an indicator of MOW strength in this study. The MOW indicator suggests that the MOW strengthened during MIS 1, MIS 5, MIS 7, MIS 9, MIS 11, MIS 13, MIS 15, MIS 17, early MIS 18 to late MIS 19, MIS 21, MISs 23-25, MISs 28-30, early MIS 34 to MIS 35, early MIS 36 to late MIS 37 and MIS 40 with a similar to 100 kyr cycle. Superimposed on the long-term variability of the MOW current, the similar to 41-kyr and similar to 20-kyr cyclic fluctuations are also evident, whereby the similar to 41-kyr cycle is more significant. The results of cross-spectral analyses indicate that the similar to 20-kyr cyclic variation in the MOW intensity was drived by the precession forcing; the similar to 41-kyr cyclic variation in the pre- MPT MOW dynamics and the similar to 100-kyr cyclic variation in the post-MPT MOW dynamics were strongly controlled by the Earth's obliquity. The variation in the abundance of the elevated ... Article in Journal/Newspaper North Atlantic Northeast Atlantic Universidade do Algarve: Sapienta Quaternary Science Reviews 247 106567 |
institution |
Open Polar |
collection |
Universidade do Algarve: Sapienta |
op_collection_id |
ftunivalgarve |
language |
English |
topic |
Benthic foraminifera Stable oxygen and carbon isotopes Middle pleistocene transition Mediterranean outflow water Bottom water ventilation Physical geography |
spellingShingle |
Benthic foraminifera Stable oxygen and carbon isotopes Middle pleistocene transition Mediterranean outflow water Bottom water ventilation Physical geography Guo, Qimei Li, Baohua Voelker, Antje Kim, Jin-Kyoung Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin |
topic_facet |
Benthic foraminifera Stable oxygen and carbon isotopes Middle pleistocene transition Mediterranean outflow water Bottom water ventilation Physical geography |
description |
Reconstruction of the Mediterranean Outflow Water (MOW) dynamics in the geologic past contributes to exploring its influence on the North Atlantic Ocean circulation and global climate. The middle Pleistocene transition (MPT) is one of the most important characteristics of Quaternary climate change, but until now, research on the MOW variability during this time interval has been limited. To decipher the MOW variability over the last 1.3 myr, this work presents the first continuous and high-resolution (similar to 2 kyr) foraminiferal stable oxygen and carbon isotopes and benthic foraminiferal records from Integrated Ocean Drilling Program (IODP) Site U1391, which was drilled off the Portuguese margin in the Northeast Atlantic Ocean and is currently bathed by the lower MOW core. Based on spectral analysis results of the foraminiferal delta O-18 record, the MPT peaked from 0.9 to 0.7 Ma. The 'epibenthos group' was previously found attached to elevated substrates only within the MOW current and more abundant at higher current velocities, so the relative abundance of the 'elevated epibenthos group' was adopted as an indicator of MOW strength in this study. The MOW indicator suggests that the MOW strengthened during MIS 1, MIS 5, MIS 7, MIS 9, MIS 11, MIS 13, MIS 15, MIS 17, early MIS 18 to late MIS 19, MIS 21, MISs 23-25, MISs 28-30, early MIS 34 to MIS 35, early MIS 36 to late MIS 37 and MIS 40 with a similar to 100 kyr cycle. Superimposed on the long-term variability of the MOW current, the similar to 41-kyr and similar to 20-kyr cyclic fluctuations are also evident, whereby the similar to 41-kyr cycle is more significant. The results of cross-spectral analyses indicate that the similar to 20-kyr cyclic variation in the MOW intensity was drived by the precession forcing; the similar to 41-kyr cyclic variation in the pre- MPT MOW dynamics and the similar to 100-kyr cyclic variation in the post-MPT MOW dynamics were strongly controlled by the Earth's obliquity. The variation in the abundance of the elevated ... |
format |
Article in Journal/Newspaper |
author |
Guo, Qimei Li, Baohua Voelker, Antje Kim, Jin-Kyoung |
author_facet |
Guo, Qimei Li, Baohua Voelker, Antje Kim, Jin-Kyoung |
author_sort |
Guo, Qimei |
title |
Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin |
title_short |
Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin |
title_full |
Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin |
title_fullStr |
Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin |
title_full_unstemmed |
Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin |
title_sort |
mediterranean outflow water dynamics across the middle pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the portuguese margin |
publisher |
Elsevier |
publishDate |
2020 |
url |
http://hdl.handle.net/10400.1/16352 https://doi.org/10.1016/j.quascirev.2020.106567 |
genre |
North Atlantic Northeast Atlantic |
genre_facet |
North Atlantic Northeast Atlantic |
op_relation |
info:eu-repo/grantAgreement/EC/FP7/228344/EU 0277-3791 http://hdl.handle.net/10400.1/16352 doi:10.1016/j.quascirev.2020.106567 |
op_rights |
restrictedAccess |
op_doi |
https://doi.org/10.1016/j.quascirev.2020.106567 |
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Quaternary Science Reviews |
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247 |
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106567 |
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