Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera
To understand bottom water variability in the subtropical northwestern Pacific, bottom water temperatures (BWTs), carbon isotopes (δ13C), and oxygen isotopes of seawater (δ18Ow) at a water depth of 1166 m were reconstructed from 26 kyr BP to present. A new regional Mg / Ca calibration for the benthi...
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00016343 2023-05-15T17:52:42+02:00 Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera Kubota, Y. Kimoto, K. Itaki, T. Yokoyama, Y. Miyairi, Y. Matsuzaki, H. 2015-06 electronic https://doi.org/10.5194/cp-11-803-2015 https://noa.gwlb.de/receive/cop_mods_00016343 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016298/cp-11-803-2015.pdf https://cp.copernicus.org/articles/11/803/2015/cp-11-803-2015.pdf eng eng Copernicus Publications Climate of the Past -- http://www.copernicus.org/EGU/cp/cp/published_papers.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2217985 -- 1814-9332 https://doi.org/10.5194/cp-11-803-2015 https://noa.gwlb.de/receive/cop_mods_00016343 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016298/cp-11-803-2015.pdf https://cp.copernicus.org/articles/11/803/2015/cp-11-803-2015.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2015 ftnonlinearchiv https://doi.org/10.5194/cp-11-803-2015 2022-02-08T22:54:12Z To understand bottom water variability in the subtropical northwestern Pacific, bottom water temperatures (BWTs), carbon isotopes (δ13C), and oxygen isotopes of seawater (δ18Ow) at a water depth of 1166 m were reconstructed from 26 kyr BP to present. A new regional Mg / Ca calibration for the benthic foraminifera Cibicidoides wuellerstorfi (type B) was established to convert the benthic Mg / Ca value to BWT, based on 26 surface sediment samples and two core-top samples retrieved around Okinawa Island. During the Last Glacial Maximum (LGM), the δ18Ow in the intermediate water in the northwestern South Pacific was ~0.4‰ lower than in the deep South Pacific, indicating a greater vertical salinity gradient than at present. This salinity (and probably density) structure would have led to stratification in the intermediate and deep Pacific, which would, in turn, have greatly influenced carbon storage during the glacial time. The benthic Mg / Ca and δ18Ow records suggest changes that seem to follow Heinrich event 1 (H1) and the Bølling–Alleød (B/A) and Younger Dryas (YD) intervals, with BWT higher during H1 (~17 kyr BP) and YD (~12 kyr BP) and lower during B/A (~14 kyr BP). The warming in the bottom water during H1 suggests increased contribution of North Pacific Intermediate Water (NPIW) to the subtropical northwestern Pacific and decreased upwelling of cooler waters from the abyssal North Pacific. During the interval from 17 to 14.5 kyr BP, the BWT tended to decrease successively in association with a decrease in δ13C values, presumably as a result of increased upwelling of the abyssal waters to the intermediate depths of the North Pacific caused by shoaling and enhancement of the southward return flow of Pacific Deep Water (PDW). During the Holocene, the millennial- to sub-millennial-scale variations in the BWT generally correlate with the sea surface temperatures in the Okhotsk Sea, the source region of the NPIW, suggesting that changes in the BWT are linked to changes in the NPIW production rate. Article in Journal/Newspaper okhotsk sea Niedersächsisches Online-Archiv NOA Okhotsk Pacific Climate of the Past 11 6 803 824 |
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Niedersächsisches Online-Archiv NOA |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Kubota, Y. Kimoto, K. Itaki, T. Yokoyama, Y. Miyairi, Y. Matsuzaki, H. Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera |
topic_facet |
article Verlagsveröffentlichung |
description |
To understand bottom water variability in the subtropical northwestern Pacific, bottom water temperatures (BWTs), carbon isotopes (δ13C), and oxygen isotopes of seawater (δ18Ow) at a water depth of 1166 m were reconstructed from 26 kyr BP to present. A new regional Mg / Ca calibration for the benthic foraminifera Cibicidoides wuellerstorfi (type B) was established to convert the benthic Mg / Ca value to BWT, based on 26 surface sediment samples and two core-top samples retrieved around Okinawa Island. During the Last Glacial Maximum (LGM), the δ18Ow in the intermediate water in the northwestern South Pacific was ~0.4‰ lower than in the deep South Pacific, indicating a greater vertical salinity gradient than at present. This salinity (and probably density) structure would have led to stratification in the intermediate and deep Pacific, which would, in turn, have greatly influenced carbon storage during the glacial time. The benthic Mg / Ca and δ18Ow records suggest changes that seem to follow Heinrich event 1 (H1) and the Bølling–Alleød (B/A) and Younger Dryas (YD) intervals, with BWT higher during H1 (~17 kyr BP) and YD (~12 kyr BP) and lower during B/A (~14 kyr BP). The warming in the bottom water during H1 suggests increased contribution of North Pacific Intermediate Water (NPIW) to the subtropical northwestern Pacific and decreased upwelling of cooler waters from the abyssal North Pacific. During the interval from 17 to 14.5 kyr BP, the BWT tended to decrease successively in association with a decrease in δ13C values, presumably as a result of increased upwelling of the abyssal waters to the intermediate depths of the North Pacific caused by shoaling and enhancement of the southward return flow of Pacific Deep Water (PDW). During the Holocene, the millennial- to sub-millennial-scale variations in the BWT generally correlate with the sea surface temperatures in the Okhotsk Sea, the source region of the NPIW, suggesting that changes in the BWT are linked to changes in the NPIW production rate. |
format |
Article in Journal/Newspaper |
author |
Kubota, Y. Kimoto, K. Itaki, T. Yokoyama, Y. Miyairi, Y. Matsuzaki, H. |
author_facet |
Kubota, Y. Kimoto, K. Itaki, T. Yokoyama, Y. Miyairi, Y. Matsuzaki, H. |
author_sort |
Kubota, Y. |
title |
Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera |
title_short |
Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera |
title_full |
Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera |
title_fullStr |
Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera |
title_full_unstemmed |
Bottom water variability in the subtropical northwestern Pacific from 26 kyr BP to present based on Mg / Ca and stable carbon and oxygen isotopes of benthic foraminifera |
title_sort |
bottom water variability in the subtropical northwestern pacific from 26 kyr bp to present based on mg / ca and stable carbon and oxygen isotopes of benthic foraminifera |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/cp-11-803-2015 https://noa.gwlb.de/receive/cop_mods_00016343 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016298/cp-11-803-2015.pdf https://cp.copernicus.org/articles/11/803/2015/cp-11-803-2015.pdf |
geographic |
Okhotsk Pacific |
geographic_facet |
Okhotsk Pacific |
genre |
okhotsk sea |
genre_facet |
okhotsk sea |
op_relation |
Climate of the Past -- http://www.copernicus.org/EGU/cp/cp/published_papers.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2217985 -- 1814-9332 https://doi.org/10.5194/cp-11-803-2015 https://noa.gwlb.de/receive/cop_mods_00016343 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016298/cp-11-803-2015.pdf https://cp.copernicus.org/articles/11/803/2015/cp-11-803-2015.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/cp-11-803-2015 |
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Climate of the Past |
container_volume |
11 |
container_issue |
6 |
container_start_page |
803 |
op_container_end_page |
824 |
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1766160403667091456 |