The Antarctic ice core chronology (AICC2012)

• Main Authors: Bazin, Lucie, Landais, Amaëlle, Lemieux-Dudon, Bénédicte, Toyé Mahamadou Kele, H, Veres, Daniel, Parrenin, Frédéric, Martinerie, Patricia, Ritz, Catherine, Capron, Emilie, Lipenkov, Vladimir Ya, Loutre, Marie-France, Raynaud, Dominique, Vinther, Bo Møllesøe, Svensson, Anders M, Rasmussen, Sune Olander, Severi, Mirko, Blunier, Thomas, Leuenberger, Markus Christian, Fischer, Hubertus, Masson-Delmotte, Valerie, Chappellaz, Jérôme A, Wolff, Eric William
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2013
• Subjects: EPICA; European Project for Ice Coring in Antarctica; Greenland Ice Core Projects; GRIP/GISP/NGRIP; Antarc*; Antarctic; Antarctica; GISP; Greenland; Greenland ice core; GRIP; ice core; NGRIP
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.824894; https://doi.org/10.1594/PANGAEA.824894

Abstract of Bazin et al. (2013): An accurate and coherent chronological framework is essential for the interpretation of climatic and environmental records obtained from deep polar ice cores. Until now, one common ice core age scale had been developed based on an inverse dating method (Datice), combining glaciological modelling with absolute and stratigraphic markers between 4 ice cores covering the last 50 ka (thousands of years before present) (Lemieux-Dudon et al., 2010). In this paper, together with the companion paper of Veres et al. (2013), we present an extension of this work back to 800 ka for the NGRIP, TALDICE, EDML, Vostok and EDC ice cores using an improved version of the Datice tool. The AICC2012 (Antarctic Ice Core Chronology 2012) chronology includes numerous new gas and ice stratigraphic links as well as improved evaluation of background and associated variance scenarios. This paper concentrates on the long timescales between 120-800 ka. In this framework, new measurements of d18Oatm over Marine Isotope Stage (MIS) 11-12 on EDC and a complete d18Oatm record of the TALDICE ice cores permit us to derive additional orbital gas age constraints. The coherency of the different orbitally deduced ages (from d18Oatm, dO2/N2 and air content) has been verified before implementation in AICC2012. The new chronology is now independent of other archives and shows only small differences, most of the time within the original uncertainty range calculated by Datice, when compared with the previous ice core reference age scale EDC3, the Dome F chronology, or using a comparison between speleothems and methane. For instance, the largest deviation between AICC2012 and EDC3 (5.4 ka) is obtained around MIS 12. Despite significant modifications of the chronological constraints around MIS 5, now independent of speleothem records in AICC2012, the date of Termination II is very close to the EDC3 one. Abstract of Veres et al. (2013): The deep polar ice cores provide reference records commonly employed in global correlation of ...