Antarctic ice sheet sensitivity to atmospheric CO 2 variations in the early to mid-Miocene

SMS Science Team

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Geological records from the Antarctic margin offer direct evidence of environmental variability at high southern latitudes and provide insight regarding ice sheet sensitivity to past climate change. The early to mid-Miocene (23-14 Mya) is a compelling interval to study as global temperatures and atmospheric CO 2 concentrations were similar to those projected for coming centuries. Importantly, this time interval includes the Miocene Climatic Optimum, a period of global warmth during which average surface temperatures were 3-4 °C higher than today. Miocene sediments in the ANDRILL-2A drill core from the Western Ross Sea, Antarctica, indicate that the Antarctic ice sheet (AIS) was highly variable through this key time interval. A multiproxy dataset derived from the core identifies four distinct environmental motifs based on changes in sedimentary facies, fossil assemblages, geochemistry, and paleotemperature. Four major disconformities in the drill core coincide with regional seismic discontinuities and reflect transient expansion of grounded ice across the Ross Sea. They correlate with major positive shifts in benthic oxygen isotope records and generally coincide with intervals when atmospheric CO 2 concentrations were at or below preindustrial levels (∼280 ppm). Five intervals reflect ice sheet minima and air temperatures warm enough for substantial ice mass loss during episodes of high (∼500 ppm) atmospheric CO 2 . These new drill core data and associated ice sheet modeling experiments indicate that polar climate and the AIS were highly sensitive to relatively small changes in atmospheric CO 2 during the early to mid-Miocene.

Original languageEnglish
Pages (from-to)3453-3458
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume113
Issue number13
DOIs
StatePublished - 29 Mar 2016

Fingerprint

ice sheet
Miocene
ice
fossil assemblage
paleotemperature
Hypsithermal
geological record
oxygen isotope
discontinuity
surface temperature
air temperature
geochemistry
climate change
climate
sediment
modeling
experiment
temperature
sea

Keywords

  • Antarctica
  • Climate Optimum
  • Ice sheet
  • Miocene
  • Ross Sea

Cite this

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title = "Antarctic ice sheet sensitivity to atmospheric CO 2 variations in the early to mid-Miocene",
abstract = "Geological records from the Antarctic margin offer direct evidence of environmental variability at high southern latitudes and provide insight regarding ice sheet sensitivity to past climate change. The early to mid-Miocene (23-14 Mya) is a compelling interval to study as global temperatures and atmospheric CO 2 concentrations were similar to those projected for coming centuries. Importantly, this time interval includes the Miocene Climatic Optimum, a period of global warmth during which average surface temperatures were 3-4 °C higher than today. Miocene sediments in the ANDRILL-2A drill core from the Western Ross Sea, Antarctica, indicate that the Antarctic ice sheet (AIS) was highly variable through this key time interval. A multiproxy dataset derived from the core identifies four distinct environmental motifs based on changes in sedimentary facies, fossil assemblages, geochemistry, and paleotemperature. Four major disconformities in the drill core coincide with regional seismic discontinuities and reflect transient expansion of grounded ice across the Ross Sea. They correlate with major positive shifts in benthic oxygen isotope records and generally coincide with intervals when atmospheric CO 2 concentrations were at or below preindustrial levels (∼280 ppm). Five intervals reflect ice sheet minima and air temperatures warm enough for substantial ice mass loss during episodes of high (∼500 ppm) atmospheric CO 2 . These new drill core data and associated ice sheet modeling experiments indicate that polar climate and the AIS were highly sensitive to relatively small changes in atmospheric CO 2 during the early to mid-Miocene.",
keywords = "Antarctica, Climate Optimum, Ice sheet, Miocene, Ross Sea",
author = "{SMS Science Team} and Richard Levy and David Harwood and Fabio Florindo and Francesca Sangiorgi and Robert Tripati and {von Eynatten}, Hilmar and Edward Gasson and Gerhard Kuhn and Aradhna Tripati and Robert Deconto and Christopher Fielding and Brad Field and Nicholas Golledge and Robert McKay and Timothy Naish and Matthew Olney and David Pollard and Stefan Schouten and Franco Talarico and Sophie Warny and Veronica Willmott and Gary Acton and Kurt Panter and Timothy Paulsen and Marco Taviani and Rosemary Askin and Clifford Atkins and Kari Bassett and Alan Beu and Brian Blackstone and Gregory Browne and Alessandro Ceregato and Rosemary Cody and Gianluca Cornamusini and Sveva Corrado and {Del Carlo}, Paola and {Di Vincenzo}, Gianfranco and Gavin Dunbar and Candice Falk and Tracy Frank and Giovanna Giorgetti and Thomas Grelle and Zi Gui and David Handwerger and Michael Hannah and Harwood, {David M.} and Dan Hauptvogel and Travis Hayden and Stuart Henrys and Stefan Hoffmann",
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Antarctic ice sheet sensitivity to atmospheric CO 2 variations in the early to mid-Miocene . / SMS Science Team.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 113, No. 13, 29.03.2016, p. 3453-3458.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Antarctic ice sheet sensitivity to atmospheric CO 2 variations in the early to mid-Miocene

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AU - Levy, Richard

AU - Harwood, David

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AU - Schouten, Stefan

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AU - Willmott, Veronica

AU - Acton, Gary

AU - Panter, Kurt

AU - Paulsen, Timothy

AU - Taviani, Marco

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AU - Di Vincenzo, Gianfranco

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AU - Frank, Tracy

AU - Giorgetti, Giovanna

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AU - Handwerger, David

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KW - Antarctica

KW - Climate Optimum

KW - Ice sheet

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KW - Ross Sea

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