Evolution of the early Antarctic ice ages
Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-se...
Published in: | Proceedings of the National Academy of Sciences |
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Online Access: | http://hdl.handle.net/11564/666056 https://doi.org/10.1073/pnas.1615440114 https://www.pnas.org/content/114/15/3867.long |
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ftunivchietiiris:oai:ricerca.unich.it:11564/666056 2024-02-11T09:57:25+01:00 Evolution of the early Antarctic ice ages Liebrand, D. de Bakker, A. T. M. Beddow, H. M. Wilson, P. A. Bohaty, S. M. Ruessink, G. Pälike, H. Batenburg, S. J. Hilgen, F. J. Hodell, D. A. Huck, C. E. Kroon, D. RAFFI, Isabella Saes, M. J. M. van Dijk, A. E. Lourens, L. J. Liebrand, D. de Bakker, A. T. M. Beddow, H. M. Wilson, P. A. Bohaty, S. M. Ruessink, G. Pälike, H. Batenburg, S. J. Hilgen, F. J. Hodell, D. A. Huck, C. E. Kroon, D. Raffi, Isabella Saes, M. J. M. van Dijk, A. E. Lourens, L. J. 2017 ELETTRONICO http://hdl.handle.net/11564/666056 https://doi.org/10.1073/pnas.1615440114 https://www.pnas.org/content/114/15/3867.long eng eng info:eu-repo/semantics/altIdentifier/pmid/28348211 info:eu-repo/semantics/altIdentifier/wos/WOS:000398789800040 volume:114 issue:15 firstpage:3867 lastpage:3872 numberofpages:6 journal:PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA http://hdl.handle.net/11564/666056 doi:10.1073/pnas.1615440114 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85032158491 https://www.pnas.org/content/114/15/3867.long info:eu-repo/semantics/openAccess Oligocene−Miocene bispectral analysi early Antarctic ice sheet glacial−interglacial cycle geometrie unipolar icehouse info:eu-repo/semantics/article 2017 ftunivchietiiris https://doi.org/10.1073/pnas.1615440114 2024-01-23T23:16:58Z Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-sea oxygen isotope (δ18O) record from the South Atlantic Ocean spanning an interval between 30.1 My and 17.1 My ago. The record displays major oscillations in deep-sea temperature and Antarctic ice volume in response to the ∼110-ky eccentricity modulation of precession. Conservative minimum ice volume estimates show that waxing and waning of at least ∼85 to 110% of the volume of the present East Antarctic Ice Sheet is required to explain many of the ∼110-ky cycles. Antarctic ice sheets were typically largest during repeated glacial cycles of the mid-Oligocene (∼28.0 My to ∼26.3 My ago) and across the Oligocene−Miocene Transition (∼23.0 My ago). However, the high-amplitude glacial−interglacial cycles of the mid-Oligocene are highly symmetrical, indicating a more direct response to eccentricity modulation of precession than their Early Miocene counterparts, which are distinctly asymmetrical—indicative of prolonged ice buildup and delayed, but rapid, glacial terminations. We hypothesize that the long-term transition to a warmer climate state with sawtooth-shaped glacial cycles in the Early Miocene was brought about by subsidence and glacial erosion in West Antarctica during the Late Oligocene and/or a change in the variability of atmospheric CO2 levels on astronomical time scales that is not yet captured in existing proxy reconstructions. © 2017, National Academy of Sciences. All rights reserved. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice cap Ice Sheet South Atlantic Ocean West Antarctica ARUd'A - Archivio Istituzionale della ricerca dell'università Chieti-Pescara (IRIS) Antarctic West Antarctica East Antarctic Ice Sheet Proceedings of the National Academy of Sciences 114 15 3867 3872 |
institution |
Open Polar |
collection |
ARUd'A - Archivio Istituzionale della ricerca dell'università Chieti-Pescara (IRIS) |
op_collection_id |
ftunivchietiiris |
language |
English |
topic |
Oligocene−Miocene bispectral analysi early Antarctic ice sheet glacial−interglacial cycle geometrie unipolar icehouse |
spellingShingle |
Oligocene−Miocene bispectral analysi early Antarctic ice sheet glacial−interglacial cycle geometrie unipolar icehouse Liebrand, D. de Bakker, A. T. M. Beddow, H. M. Wilson, P. A. Bohaty, S. M. Ruessink, G. Pälike, H. Batenburg, S. J. Hilgen, F. J. Hodell, D. A. Huck, C. E. Kroon, D. RAFFI, Isabella Saes, M. J. M. van Dijk, A. E. Lourens, L. J. Evolution of the early Antarctic ice ages |
topic_facet |
Oligocene−Miocene bispectral analysi early Antarctic ice sheet glacial−interglacial cycle geometrie unipolar icehouse |
description |
Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-sea oxygen isotope (δ18O) record from the South Atlantic Ocean spanning an interval between 30.1 My and 17.1 My ago. The record displays major oscillations in deep-sea temperature and Antarctic ice volume in response to the ∼110-ky eccentricity modulation of precession. Conservative minimum ice volume estimates show that waxing and waning of at least ∼85 to 110% of the volume of the present East Antarctic Ice Sheet is required to explain many of the ∼110-ky cycles. Antarctic ice sheets were typically largest during repeated glacial cycles of the mid-Oligocene (∼28.0 My to ∼26.3 My ago) and across the Oligocene−Miocene Transition (∼23.0 My ago). However, the high-amplitude glacial−interglacial cycles of the mid-Oligocene are highly symmetrical, indicating a more direct response to eccentricity modulation of precession than their Early Miocene counterparts, which are distinctly asymmetrical—indicative of prolonged ice buildup and delayed, but rapid, glacial terminations. We hypothesize that the long-term transition to a warmer climate state with sawtooth-shaped glacial cycles in the Early Miocene was brought about by subsidence and glacial erosion in West Antarctica during the Late Oligocene and/or a change in the variability of atmospheric CO2 levels on astronomical time scales that is not yet captured in existing proxy reconstructions. © 2017, National Academy of Sciences. All rights reserved. |
author2 |
Liebrand, D. de Bakker, A. T. M. Beddow, H. M. Wilson, P. A. Bohaty, S. M. Ruessink, G. Pälike, H. Batenburg, S. J. Hilgen, F. J. Hodell, D. A. Huck, C. E. Kroon, D. Raffi, Isabella Saes, M. J. M. van Dijk, A. E. Lourens, L. J. |
format |
Article in Journal/Newspaper |
author |
Liebrand, D. de Bakker, A. T. M. Beddow, H. M. Wilson, P. A. Bohaty, S. M. Ruessink, G. Pälike, H. Batenburg, S. J. Hilgen, F. J. Hodell, D. A. Huck, C. E. Kroon, D. RAFFI, Isabella Saes, M. J. M. van Dijk, A. E. Lourens, L. J. |
author_facet |
Liebrand, D. de Bakker, A. T. M. Beddow, H. M. Wilson, P. A. Bohaty, S. M. Ruessink, G. Pälike, H. Batenburg, S. J. Hilgen, F. J. Hodell, D. A. Huck, C. E. Kroon, D. RAFFI, Isabella Saes, M. J. M. van Dijk, A. E. Lourens, L. J. |
author_sort |
Liebrand, D. |
title |
Evolution of the early Antarctic ice ages |
title_short |
Evolution of the early Antarctic ice ages |
title_full |
Evolution of the early Antarctic ice ages |
title_fullStr |
Evolution of the early Antarctic ice ages |
title_full_unstemmed |
Evolution of the early Antarctic ice ages |
title_sort |
evolution of the early antarctic ice ages |
publishDate |
2017 |
url |
http://hdl.handle.net/11564/666056 https://doi.org/10.1073/pnas.1615440114 https://www.pnas.org/content/114/15/3867.long |
geographic |
Antarctic West Antarctica East Antarctic Ice Sheet |
geographic_facet |
Antarctic West Antarctica East Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Ice cap Ice Sheet South Atlantic Ocean West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice cap Ice Sheet South Atlantic Ocean West Antarctica |
op_relation |
info:eu-repo/semantics/altIdentifier/pmid/28348211 info:eu-repo/semantics/altIdentifier/wos/WOS:000398789800040 volume:114 issue:15 firstpage:3867 lastpage:3872 numberofpages:6 journal:PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA http://hdl.handle.net/11564/666056 doi:10.1073/pnas.1615440114 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85032158491 https://www.pnas.org/content/114/15/3867.long |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1073/pnas.1615440114 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
114 |
container_issue |
15 |
container_start_page |
3867 |
op_container_end_page |
3872 |
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1790609716643102720 |