Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean
Eight- to ten-point depth profiles (from 1200 to 4800 m water depth) of oxygen and carbon isotopic values derived from benthic foraminifera, averaged over selected times in the past 160 ka, are presented. The data are from 10 sediment cores off eastern New Zealand, mainly North Chatham Rise. This li...
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:522 2023-05-15T13:32:21+02:00 Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean McCave, I. N. Carter, L. Hall, I. R. 2008 application/pdf http://eprints.esc.cam.ac.uk/522/ http://eprints.esc.cam.ac.uk/522/1/McCave_Quat_Sci_Rev_27_19-20_2008.pdf https://doi.org/10.1016/j.quascirev.2008.07.010 en eng http://eprints.esc.cam.ac.uk/522/1/McCave_Quat_Sci_Rev_27_19-20_2008.pdf McCave, I. N. and Carter, L. and Hall, I. R. (2008) Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean. Quaternary Science Reviews, 27 (19-20). pp. 1886-1908. DOI https://doi.org/10.1016/j.quascirev.2008.07.010 <https://doi.org/10.1016/j.quascirev.2008.07.010> 01 - Climate Change and Earth-Ocean Atmosphere Systems Article PeerReviewed 2008 ftucambridgeesc https://doi.org/10.1016/j.quascirev.2008.07.010 2020-08-27T18:08:35Z Eight- to ten-point depth profiles (from 1200 to 4800 m water depth) of oxygen and carbon isotopic values derived from benthic foraminifera, averaged over selected times in the past 160 ka, are presented. The data are from 10 sediment cores off eastern New Zealand, mainly North Chatham Rise. This lies under the Deep Western Boundary Current in the Southwest Pacific and is the main point of entry for several water masses into the Pacific Ocean. The benthic isotopic profiles are related to the structure of water masses at present and inferred for the past. These have retained a constant structure of Lower Circumpolar Deep Water–Upper Circumpolar Deep Water/North Pacific Deep Water–Antarctic Intermediate Water with no apparent changes in the depths of water mass boundaries between glacial and interglacial states. Sortable silt particle size data for four cores are also examined to show that the vigour of the inflow to the Pacific, while variable, appears to have remained fairly constant on average. Among the lowest Last Glacial Maximum values of benthic d13C in the world ocean (1.03& based on Cibicidoides wu¨llerstorfi) occurs here at w2200 m. Comparable values occur in the Atlantic sector of the Southern Ocean, while those from the rest of the Pacific are distinctly higher, confirming that the Southern Ocean was the source for the unventilated/nutrient-enriched water seen here. Oxygen and carbon isotopic data are compatible with a glacial cold deep water mass of high salinity, but lower nutrient content (or better ventilated), below w3500 m depth. This contrasts with the South Atlantic where unventilated/nutrient-enriched water extends all the way to the sea bed. Comparison with previous studies also suggests that the deeper reaches of the Antarctic Circumpolar Current below w3500 m are not homogeneous all around the Southern Ocean, with the Kerguelen Plateau and/or the Macquarie-Balleny Ridges posing barriers to the eastward spread of the deepest low-d13C water out of the South Atlantic in glacials. These barriers, combined with inferred high density of bottom waters, restricted inter-basin exchange and allow three glacial domains dominated by bottom waters from Weddell Sea, Adelie Coast and Ross Sea to be defined. We suggest that the Ross Sea was the main source of the deep water entering the Pacific below w3500 m. Article in Journal/Newspaper Antarc* Antarctic Ross Sea Southern Ocean Weddell Sea University of Cambridge, Department of Earth Sciences: ESC Publications Antarctic Kerguelen New Zealand Pacific Ross Sea Southern Ocean The Antarctic Weddell Weddell Sea Quaternary Science Reviews 27 19-20 1886 1908 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
spellingShingle |
01 - Climate Change and Earth-Ocean Atmosphere Systems McCave, I. N. Carter, L. Hall, I. R. Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean |
topic_facet |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
description |
Eight- to ten-point depth profiles (from 1200 to 4800 m water depth) of oxygen and carbon isotopic values derived from benthic foraminifera, averaged over selected times in the past 160 ka, are presented. The data are from 10 sediment cores off eastern New Zealand, mainly North Chatham Rise. This lies under the Deep Western Boundary Current in the Southwest Pacific and is the main point of entry for several water masses into the Pacific Ocean. The benthic isotopic profiles are related to the structure of water masses at present and inferred for the past. These have retained a constant structure of Lower Circumpolar Deep Water–Upper Circumpolar Deep Water/North Pacific Deep Water–Antarctic Intermediate Water with no apparent changes in the depths of water mass boundaries between glacial and interglacial states. Sortable silt particle size data for four cores are also examined to show that the vigour of the inflow to the Pacific, while variable, appears to have remained fairly constant on average. Among the lowest Last Glacial Maximum values of benthic d13C in the world ocean (1.03& based on Cibicidoides wu¨llerstorfi) occurs here at w2200 m. Comparable values occur in the Atlantic sector of the Southern Ocean, while those from the rest of the Pacific are distinctly higher, confirming that the Southern Ocean was the source for the unventilated/nutrient-enriched water seen here. Oxygen and carbon isotopic data are compatible with a glacial cold deep water mass of high salinity, but lower nutrient content (or better ventilated), below w3500 m depth. This contrasts with the South Atlantic where unventilated/nutrient-enriched water extends all the way to the sea bed. Comparison with previous studies also suggests that the deeper reaches of the Antarctic Circumpolar Current below w3500 m are not homogeneous all around the Southern Ocean, with the Kerguelen Plateau and/or the Macquarie-Balleny Ridges posing barriers to the eastward spread of the deepest low-d13C water out of the South Atlantic in glacials. These barriers, combined with inferred high density of bottom waters, restricted inter-basin exchange and allow three glacial domains dominated by bottom waters from Weddell Sea, Adelie Coast and Ross Sea to be defined. We suggest that the Ross Sea was the main source of the deep water entering the Pacific below w3500 m. |
format |
Article in Journal/Newspaper |
author |
McCave, I. N. Carter, L. Hall, I. R. |
author_facet |
McCave, I. N. Carter, L. Hall, I. R. |
author_sort |
McCave, I. N. |
title |
Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean |
title_short |
Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean |
title_full |
Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean |
title_fullStr |
Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean |
title_full_unstemmed |
Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean |
title_sort |
glacial-interglacial changes in water mass structure and flow in the sw pacific ocean |
publishDate |
2008 |
url |
http://eprints.esc.cam.ac.uk/522/ http://eprints.esc.cam.ac.uk/522/1/McCave_Quat_Sci_Rev_27_19-20_2008.pdf https://doi.org/10.1016/j.quascirev.2008.07.010 |
geographic |
Antarctic Kerguelen New Zealand Pacific Ross Sea Southern Ocean The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Kerguelen New Zealand Pacific Ross Sea Southern Ocean The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Ross Sea Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Ross Sea Southern Ocean Weddell Sea |
op_relation |
http://eprints.esc.cam.ac.uk/522/1/McCave_Quat_Sci_Rev_27_19-20_2008.pdf McCave, I. N. and Carter, L. and Hall, I. R. (2008) Glacial-interglacial changes in water mass structure and flow in the SW Pacific Ocean. Quaternary Science Reviews, 27 (19-20). pp. 1886-1908. DOI https://doi.org/10.1016/j.quascirev.2008.07.010 <https://doi.org/10.1016/j.quascirev.2008.07.010> |
op_doi |
https://doi.org/10.1016/j.quascirev.2008.07.010 |
container_title |
Quaternary Science Reviews |
container_volume |
27 |
container_issue |
19-20 |
container_start_page |
1886 |
op_container_end_page |
1908 |
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1766026062496530432 |