Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 11, 2427-2437, 2017
https://doi.org/10.5194/tc-11-2427-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
02 Nov 2017
Is there 1.5-million-year-old ice near Dome C, Antarctica?
Frédéric Parrenin1, Marie G. P. Cavitte2,3, Donald D. Blankenship2, Jérôme Chappellaz1, Hubertus Fischer4, Olivier Gagliardini1, Valérie Masson-Delmotte5, Olivier Passalacqua1, Catherine Ritz1, Jason Roberts6,7, Martin J. Siegert8, and Duncan A. Young2 1Univ. Grenoble Alpes, CNRS, IRD, IGE, 38000 Grenoble, France
2Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
3Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, USA
4Climate and Environmental Physics, Physics Institute & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
5Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ/IPSL – UMR8212, Gif-Sur-Yvette, France
6Australian Antarctic Division, Kingston, 7050 Tasmania, Australia
7Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, 7001 Tasmania, Australia
8Grantham Institute and Department of Earth Science and Engineering, Imperial College London, London, UK
Abstract. Ice sheets provide exceptional archives of past changes in polar climate, regional environment and global atmospheric composition. The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC), reaching ∼ 800 000 years. Obtaining an older paleoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we use internal isochrones, identified from airborne radar coupled to ice-flow modelling to estimate the age of basal ice along transects in the Dome C area. Three glaciological properties are inferred from isochrones: surface accumulation rate, geothermal flux and the exponent of the Lliboutry velocity profile. We find that old ice (> 1.5 Myr, 1.5 million years) likely exists in two regions: one ∼ 40 km south-west of Dome C along the ice divide to Vostok, close to a secondary dome that we name Little Dome C (LDC), and a second region named North Patch (NP) located 10–30 km north-east of Dome C, in a region where the geothermal flux is apparently relatively low. Our work demonstrates the value of combining radar observations with ice flow modelling to accurately represent the true nature of ice flow, and understand the formation of ice-sheet architecture, in the centre of large ice sheets.

Citation: Parrenin, F., Cavitte, M. G. P., Blankenship, D. D., Chappellaz, J., Fischer, H., Gagliardini, O., Masson-Delmotte, V., Passalacqua, O., Ritz, C., Roberts, J., Siegert, M. J., and Young, D. A.: Is there 1.5-million-year-old ice near Dome C, Antarctica?, The Cryosphere, 11, 2427-2437, https://doi.org/10.5194/tc-11-2427-2017, 2017.
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Short summary
The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC), reaching ~ 800 000 years. Obtaining an older palaeoclimatic record from Antarctica is one of the greatest challenges of the ice core community. Here, we estimate the age of basal ice in the Dome C area. We find that old ice (> 1.5 Myr) likely exists in two regions a few tens of kilometres away from EDC: Little Dome C Patch and North Patch.
The oldest dated deep ice core drilled in Antarctica has been retrieved at EPICA Dome C (EDC),...
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