Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth
Today the deep western boundary current (DWBC) east of New Zealand is the most important route for deep water entering the Pacific Ocean. Large-scale changes in deep water circulation patterns are thought to have been associated with the development of the East Antarctic Ice Sheet (EAIS) close to th...
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American Geophysical Union
2003
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Online Access: | https://orca.cardiff.ac.uk/id/eprint/30522/ https://doi.org/10.1029/2002PA000817 https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf |
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:30522 2023-06-11T04:04:28+02:00 Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth Hall, Ian Robert McCave, I. Nicholas Zahn, Rainer Carter, Lionel Knutz, Paul C. Weedon, Graham P. 2003-06 application/pdf https://orca.cardiff.ac.uk/id/eprint/30522/ https://doi.org/10.1029/2002PA000817 https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf en eng American Geophysical Union https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf Hall, Ian Robert https://orca.cardiff.ac.uk/view/cardiffauthors/A002402L.html orcid:0000-0001-6960-1419 orcid:0000-0001-6960-1419, McCave, I. Nicholas, Zahn, Rainer, Carter, Lionel, Knutz, Paul C. and Weedon, Graham P. 2003. Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth. Paleoceanography 18 (2) , 1040. 10.1029/2002PA000817 https://doi.org/10.1029/2002PA000817 file https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf doi:10.1029/2002PA000817 GC Oceanography Article PeerReviewed 2003 ftunivcardiff https://doi.org/10.1029/2002PA000817 2023-05-04T22:33:25Z Today the deep western boundary current (DWBC) east of New Zealand is the most important route for deep water entering the Pacific Ocean. Large-scale changes in deep water circulation patterns are thought to have been associated with the development of the East Antarctic Ice Sheet (EAIS) close to the main source of bottom water for the DWBC. Here we reconstruct the changing speed of the southwest Pacific DWBC during the middle Miocene from ∼15.5–12.5 Ma, a period of significant global ice accumulation associated with EAIS growth. Sortable silt mean grain sizes from Ocean Drilling Program Site 1123 reveal variability in the speed of the Pacific inflow on the timescale of the 41 kyr orbital obliquity cycle. Similar orbital period flow changes have recently been demonstrated for the Pleistocene epoch. Collectively, these observations suggest that a strong coupling between changes in the speed of the deep Pacific inflow and high-latitude climate forcing may have been a persistent feature of the global thermohaline circulation system for at least the past 15 Myr. Furthermore, long-term changes in flow speed suggest an intensification of the DWBC under an inferred increase in Southern Component Water production. This occurred at the same time as decreasing Tethyan outflow and major EAIS growth between ∼15.5 and 13.5 Ma. These results provide evidence that a major component of the deep thermohaline circulation was associated with the middle Miocene growth of the EAIS and support the view that this time interval represents an important step in the development of the Neogene icehouse climate. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Cardiff University: ORCA (Online Research @ Cardiff) Antarctic East Antarctic Ice Sheet Pacific New Zealand Paleoceanography 18 2 n/a n/a |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
topic |
GC Oceanography |
spellingShingle |
GC Oceanography Hall, Ian Robert McCave, I. Nicholas Zahn, Rainer Carter, Lionel Knutz, Paul C. Weedon, Graham P. Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth |
topic_facet |
GC Oceanography |
description |
Today the deep western boundary current (DWBC) east of New Zealand is the most important route for deep water entering the Pacific Ocean. Large-scale changes in deep water circulation patterns are thought to have been associated with the development of the East Antarctic Ice Sheet (EAIS) close to the main source of bottom water for the DWBC. Here we reconstruct the changing speed of the southwest Pacific DWBC during the middle Miocene from ∼15.5–12.5 Ma, a period of significant global ice accumulation associated with EAIS growth. Sortable silt mean grain sizes from Ocean Drilling Program Site 1123 reveal variability in the speed of the Pacific inflow on the timescale of the 41 kyr orbital obliquity cycle. Similar orbital period flow changes have recently been demonstrated for the Pleistocene epoch. Collectively, these observations suggest that a strong coupling between changes in the speed of the deep Pacific inflow and high-latitude climate forcing may have been a persistent feature of the global thermohaline circulation system for at least the past 15 Myr. Furthermore, long-term changes in flow speed suggest an intensification of the DWBC under an inferred increase in Southern Component Water production. This occurred at the same time as decreasing Tethyan outflow and major EAIS growth between ∼15.5 and 13.5 Ma. These results provide evidence that a major component of the deep thermohaline circulation was associated with the middle Miocene growth of the EAIS and support the view that this time interval represents an important step in the development of the Neogene icehouse climate. |
format |
Article in Journal/Newspaper |
author |
Hall, Ian Robert McCave, I. Nicholas Zahn, Rainer Carter, Lionel Knutz, Paul C. Weedon, Graham P. |
author_facet |
Hall, Ian Robert McCave, I. Nicholas Zahn, Rainer Carter, Lionel Knutz, Paul C. Weedon, Graham P. |
author_sort |
Hall, Ian Robert |
title |
Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth |
title_short |
Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth |
title_full |
Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth |
title_fullStr |
Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth |
title_full_unstemmed |
Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth |
title_sort |
paleocurrent reconstruction of the deep pacific inflow during the middle miocene: reflections of east antarctic ice sheet growth |
publisher |
American Geophysical Union |
publishDate |
2003 |
url |
https://orca.cardiff.ac.uk/id/eprint/30522/ https://doi.org/10.1029/2002PA000817 https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf |
geographic |
Antarctic East Antarctic Ice Sheet Pacific New Zealand |
geographic_facet |
Antarctic East Antarctic Ice Sheet Pacific New Zealand |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf Hall, Ian Robert https://orca.cardiff.ac.uk/view/cardiffauthors/A002402L.html orcid:0000-0001-6960-1419 orcid:0000-0001-6960-1419, McCave, I. Nicholas, Zahn, Rainer, Carter, Lionel, Knutz, Paul C. and Weedon, Graham P. 2003. Paleocurrent reconstruction of the deep Pacific inflow during the middle Miocene: Reflections of East Antarctic Ice Sheet growth. Paleoceanography 18 (2) , 1040. 10.1029/2002PA000817 https://doi.org/10.1029/2002PA000817 file https://orca.cardiff.ac.uk/id/eprint/30522/1/Hall%202003.pdf doi:10.1029/2002PA000817 |
op_doi |
https://doi.org/10.1029/2002PA000817 |
container_title |
Paleoceanography |
container_volume |
18 |
container_issue |
2 |
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n/a |
op_container_end_page |
n/a |
_version_ |
1768388095264161792 |