Large obliquity-paced Antarctic ice-volume fluctuations suggest melting by atmospheric and ocean warming during late Oligocene
Large obliquity-paced Antarctic ice-volume fluctuations suggest melting by atmospheric and ocean warming during late Oligocene
The late Oligocene (~27.8–23 My ago) offers an opportunity to study past climate variability under high-CO2, warmer-than-present and the unipolar (Antarctic) glaciated state. Here, we present new high-resolution geochemical records from exquisitely well-preserved benthic foraminifera for the late Oligocene, an interval for which Antarctic ice-sheet size and stability are debated. Our records indicate four obliquity-paced glacial-interglacial cycles with ice-volume changes of up to ~70% of the modern Antarctic ice-sheet. The amplitude of ice-volume change during these late Oligocene glacial-interglacial cycles is comparable to that of the late Pliocene and early Pleistocene. Ice-volume estimates for interglacials are small enough to be accommodated by a land-based Antarctic ice-sheet but, for three of the four glacials studied, our calculations imply that ice sheets likely advanced beyond the Antarctic coastline onto the shelves. Our findings suggest an Antarctic ice-sheet vulnerable to melting driven by both bottom-up (ocean) and top-down (atmospheric) warming under late Oligocene warmer-than-present climate conditions.
Brzelinski, Swaantje
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Bornemann, André
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Liebrand, Diederik
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van Peer, Tim E.
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Wilson, Paul
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Friedrich, Oliver
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22 June 2023
Brzelinski, Swaantje
c1382c55-54ca-403b-8325-f2fdb122bfdb
Bornemann, André
94f04299-fdf2-4c56-bace-b1ae4086aac9
Liebrand, Diederik
bef7cbd7-4fa7-453c-9961-c950a5b87795
van Peer, Tim E.
a854760d-ab6a-414c-ab35-d234607561a6
Wilson, Paul
f940a9f0-fa5a-4a64-9061-f0794bfbf7c6
Friedrich, Oliver
680f066c-a4b1-4647-beb3-281addc1ee17
Brzelinski, Swaantje, Bornemann, André, Liebrand, Diederik, van Peer, Tim E., Wilson, Paul and Friedrich, Oliver
(2023)
Large obliquity-paced Antarctic ice-volume fluctuations suggest melting by atmospheric and ocean warming during late Oligocene.
Communications Earth & Environment, 4 (1), [222].
(doi:10.1038/s43247-023-00864-9).
Abstract
The late Oligocene (~27.8–23 My ago) offers an opportunity to study past climate variability under high-CO2, warmer-than-present and the unipolar (Antarctic) glaciated state. Here, we present new high-resolution geochemical records from exquisitely well-preserved benthic foraminifera for the late Oligocene, an interval for which Antarctic ice-sheet size and stability are debated. Our records indicate four obliquity-paced glacial-interglacial cycles with ice-volume changes of up to ~70% of the modern Antarctic ice-sheet. The amplitude of ice-volume change during these late Oligocene glacial-interglacial cycles is comparable to that of the late Pliocene and early Pleistocene. Ice-volume estimates for interglacials are small enough to be accommodated by a land-based Antarctic ice-sheet but, for three of the four glacials studied, our calculations imply that ice sheets likely advanced beyond the Antarctic coastline onto the shelves. Our findings suggest an Antarctic ice-sheet vulnerable to melting driven by both bottom-up (ocean) and top-down (atmospheric) warming under late Oligocene warmer-than-present climate conditions.
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s43247-023-00864-9
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Accepted/In Press date: 24 May 2023
e-pub ahead of print date: 22 June 2023
Published date: 22 June 2023
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Funding Information:
We thank B. Hennrich, F. Kerschhofer, and P. Geppert for laboratory assistance, A. Bahr for his support in statistical analyses, C. Scholz and S. Rheinberger for support during ICP-OES measurements, and B. Knape, M. Greule and F. Keppler for support during stable isotope measurements. We thank the Captain, crew, JRSO technical staff, and shipboard scientists onboard the R/V JOIDES Resolution during IODP Expedition 342. This research used samples provided by the Integrated Ocean Drilling Programme (IODP). Funding for this study was provided by the German Research Foundation (grants FR2544/12 and FR2544/17 to S.B. and O.F.; BO2505/9 to A.B.), the Natural Environment Research Council (NERC) (grants NE/R018235/1 and NE/T012285/1 to T.E.v.P.; NE/K014137/1 to D.L.). P.A.W. acknowledges funding from NERC (grant NE/D006465/1) and the Royal Society (Wolfson Merit Award).
Funding Information:
We thank B. Hennrich, F. Kerschhofer, and P. Geppert for laboratory assistance, A. Bahr for his support in statistical analyses, C. Scholz and S. Rheinberger for support during ICP-OES measurements, and B. Knape, M. Greule and F. Keppler for support during stable isotope measurements. We thank the Captain, crew, JRSO technical staff, and shipboard scientists onboard the R/V JOIDES Resolution during IODP Expedition 342. This research used samples provided by the Integrated Ocean Drilling Programme (IODP). Funding for this study was provided by the German Research Foundation (grants FR2544/12 and FR2544/17 to S.B. and O.F.; BO2505/9 to A.B.), the Natural Environment Research Council (NERC) (grants NE/R018235/1 and NE/T012285/1 to T.E.v.P.; NE/K014137/1 to D.L.). P.A.W. acknowledges funding from NERC (grant NE/D006465/1) and the Royal Society (Wolfson Merit Award).
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© 2023, The Author(s).
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Local EPrints ID: 479443
URI: http://eprints.soton.ac.uk/id/eprint/479443
PURE UUID: e60c825e-6cb1-4e3c-8a9c-782d07df0381
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Date deposited: 24 Jul 2023 16:50
Last modified: 18 Mar 2024 02:51
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Author:
Swaantje Brzelinski
Author:
André Bornemann
Author:
Diederik Liebrand
Author:
Tim E. van Peer
Author:
Oliver Friedrich
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