Eccentricity pacing and rapid termination of the early Antarctic ice ages

Earth’s obliquity and eccentricity cycles are strongly imprinted on Earth’s climate and widely used to measure geological time. However, the record of these imprints on the oxygen isotope record in deep-sea benthic foraminifera (δ18Ob) shows contradictory signals that violate isotopic principles and...

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Main Authors: Peer, Tim van (Author) , Liebrand, Diederik (Author) , Taylor, Victoria (Author) , Brzelinski, Swaantje (Author) , Wolf, Iris (Author) , Bornemann, André (Author) , Friedrich, Oliver (Author) , Bohaty, Steven M. (Author) , Xuan, Chuang (Author) , Lippert, Peter C. (Author) , Wilson, Paul (Author)
Format: Article (Journal)
Language:English
Published: 2024
In: Nature Communications
Year: 2024, Volume: 15, Pages: 1-10
ISSN:2041-1723
DOI:10.1038/s41467-024-54186-1
Online Access:kostenfrei
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Author Notes:Tim E. van Peer, Diederik Liebrand, Victoria E. Taylor, Swaantje Brzelinski, Iris Wolf, André Bornemann, Oliver Friedrich, Steven M. Bohaty, Chuang Xuan, Peter C. Lippert & Paul A. Wilson
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Summary:Earth’s obliquity and eccentricity cycles are strongly imprinted on Earth’s climate and widely used to measure geological time. However, the record of these imprints on the oxygen isotope record in deep-sea benthic foraminifera (δ18Ob) shows contradictory signals that violate isotopic principles and cause controversy over climate-ice sheet interactions. Here, we present a δ18Ob record of high fidelity from International Ocean Drilling Program (IODP) Site U1406 in the northwest Atlantic Ocean. We compare our record to other records for the time interval between 28 and 20 million years ago, when Earth was warmer than today, and only Antarctic ice sheets existed. The imprint of eccentricity on δ18Ob is remarkably consistent globally whereas the obliquity signal is inconsistent between sites, indicating that eccentricity was the primary pacemaker of land ice volume. The larger eccentricity-paced early Antarctic ice ages were vulnerable to rapid termination. These findings imply that the self-stabilizing hysteresis effects of large land-based early Antarctic ice sheets were strong enough to maintain ice growth despite consecutive insolation-induced polar warming episodes. However, rapid ice age terminations indicate that resistance to melting was weaker than simulated by numerical models and regularly overpowered, sometimes abruptly.
Item Description:Online veröffentlicht: 05. Dezember 2024
Gesehen am 10.06.2025
Physical Description:Online Resource
ISSN:2041-1723
DOI:10.1038/s41467-024-54186-1