Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

CO2 drawdown following the middle Miocene expansion of the Antarctic ice sheet

Badger, Marcus Peter, Lear, Caroline Helen, Pancost, Richard D., Foster, Gavin L., Bailey, Trevor, Leng, Melanie J. and Abels, Hemmo A. 2013. CO2 drawdown following the middle Miocene expansion of the Antarctic ice sheet. Paleoceanography 28 (1) , pp. 42-53. 10.1002/palo.20015

[img]
Preview
PDF - Published Version
Download (1MB) | Preview

Abstract

The development of a permanent, stable ice sheet in East Antarctica happened during the middle Miocene, about 14 Myr (million years) ago. The middle Miocene therefore represents one of the distinct phases of rapid change in the transition from the “greenhouse” of the early Eocene to the “icehouse” of the present day. Carbonate carbon isotope records of the period immediately following the main stage of ice sheet development reveal a major perturbation in the carbon system, represented by the positive δ13C excursion known as carbon maximum 6 (“CM6”), which has traditionally been interpreted as reflecting increased burial of organic matter and atmospheric pCO2 drawdown. More recently, it has been suggested that the δ13C excursion records a negative feedback resulting from the reduction of silicate weathering and an increase in atmospheric pCO2. Here we present high-resolution multi-proxy (alkenone carbon and foraminiferal boron isotope) records of atmospheric carbon dioxide and sea surface temperature across CM6. Similar to previously published records spanning this interval, our records document a world of generally low (~300 ppm) atmospheric pCO2 at a time generally accepted to be much warmer than today. Crucially, they also reveal a pCO2 decrease with associated cooling, which demonstrates that the carbon burial hypothesis for CM6 is feasible and could have acted as a positive feedback on global cooling.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Ocean Sciences
Subjects: Q Science > QE Geology
Uncontrolled Keywords: pCO2; middle Miocene; ice sheets; alkenone carbon isotopes; boron isotopes
Additional Information: Pdf uploaded in accordance with publisher's policy at http://www.sherpa.ac.uk/romeo/issn/1944-9186/ (accessed 20/02/2014).
Publisher: American Geophysical Union
ISSN: 0883-8305
Funders: NERC
Date of First Compliant Deposit: 30 March 2016
Last Modified: 13 Jan 2018 21:16
URI: http://orca-mwe.cf.ac.uk/id/eprint/44091

Citation Data

Cited 28 times in Google Scholar. View in Google Scholar

Cited 46 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics