A new sea-level record for the Neogene/Quaternary boundary reveals transition to a more stable East Antarctic Ice Sheet

• Verfasst von: Jakob, Kim [VerfasserIn]
• Verfasst von: Wilson, Paul A. [VerfasserIn]
• Verfasst von: Pross, Jörg [VerfasserIn]
• Verfasst von: Ezard, Thomas H. G. [VerfasserIn]
• Verfasst von: Fiebig, Jens [VerfasserIn]
• Verfasst von: Repschläger, Janne [VerfasserIn]
• Verfasst von: Friedrich, Oliver [VerfasserIn]
• Titel: A new sea-level record for the Neogene/Quaternary boundary reveals transition to a more stable East Antarctic Ice Sheet
• Verf.angabe: Kim A. Jakob, Paul A. Wilson, Jörg Pross, Thomas H.G. Ezard, Jens Fiebig, Janne Repschläger, and Oliver Friedrich
• E-Jahr: 2020
• Jahr: November 23, 2020
• Umfang: 8 S.
• Teil: volume:117
• Teil: year:2020
• Teil: number:49
• Teil: pages:30980-30987
• Teil: extent:8
• Fussnoten: Published first November 23, 2020 ; Gesehen am 07.10.2021
• Titel Quelle: Enthalten in: National Academy of Sciences (Washington, DC)Proceedings of the National Academy of Sciences of the United States of America
• Ort Quelle: Washington, DC : National Acad. of Sciences, 1915
• Jahr Quelle: 2020
• Band/Heft Quelle: 117(2020), 49, Seite 30980-30987
• ISSN Quelle: 1091-6490
• DOI: doi:10.1073/pnas.2004209117
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: East Antarctic Ice Sheet
• Sach-SW: intensification of Northern Hemisphere Glaciation
• Sach-SW: ocean-cryosphere interaction
• Sach-SW: sea level
• K10plus-PPN: 1741646545

Abstract

Sea-level rise resulting from the instability of polar continental ice sheets represents a major socioeconomic hazard arising from anthropogenic warming, but the response of the largest component of Earth’s cryosphere, the East Antarctic Ice Sheet (EAIS), to global warming is poorly understood. Here we present a detailed record of North Atlantic deep-ocean temperature, global sea-level, and ice-volume change for ∼2.75 to 2.4 Ma ago, when atmospheric partial pressure of carbon dioxide (pCO2) ranged from present-day (>400 parts per million volume, ppmv) to preindustrial (<280 ppmv) values. Our data reveal clear glacial-interglacial cycles in global ice volume and sea level largely driven by the growth and decay of ice sheets in the Northern Hemisphere. Yet, sea-level values during Marine Isotope Stage (MIS) 101 (∼2.55 Ma) also signal substantial melting of the EAIS, and peak sea levels during MIS G7 (∼2.75 Ma) and, perhaps, MIS G1 (∼2.63 Ma) are also suggestive of EAIS instability. During the succeeding glacial-interglacial cycles (MIS 100 to 95), sea levels were distinctly lower than before, strongly suggesting a link between greater stability of the EAIS and increased land-ice volumes in the Northern Hemisphere. We propose that lower sea levels driven by ice-sheet growth in the Northern Hemisphere decreased EAIS susceptibility to ocean melting. Our findings have implications for future EAIS vulnerability to a rapidly warming world.