EGU25-11227, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-11227
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
First 17O-excess record for the EPICA Dome C deep ice core
Emma Samin1, Amaëlle Landais1, Thomas Combacal1, Antoine Grisart1, Jean Jouzel1, Valérie Masson-Delmotte1, Bénédicte Minster1, Frédéric Prié1, and Barbara Stenni2
Emma Samin et al.
  • 1Laboratoire des Sciences du Climat et de l’Environnement (IPSL/CEA-CNRS-UVSQ UMR 8212), CEA Saclay, 91191 Gif-sur-Yvette CEDEX, France (emma.samin@lsce.ipsl.fr))
  • 2Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice, Venice, Italy

Water isotopes records in polar ice cores provide insights into past climate variability through oxygen and hydrogen fractionation. The EPICA Dome C (EDC) deep ice core in Antarctica has provided δ18O and δD records over the last 800,000 years, which are known to be valuable proxies for tracking temperature variation. Combining both, the deuterium excess (d-excess = δD − 8 * δ18O) gives us information on the hydrological cycle, as it is known to reflect the evaporation stage and air mass transport. However, it is sensitive to the variations of seawater δ18O and the distillation effect of the air mass. The 17O-excess (17O-excess = ln(δ17O+1) − 0.528×ln(δ18O+1)) can provide complementary information to d-excess as it is rather sensitive to air mass mixing and supersaturated conditions along the path.

Here, we present the first record of 17O-excess for the EDC ice core, spanning over the past 126,000 to 800,000 years. We aim to investigate the potential of this tool for interpreting the reorganization of the hydrological cycle in the Southern Hemisphere. 17O-excess variations along the core show the alternation of glacial and interglacial cycles, comparable with other water isotopes and related to orbital parameters. We scrutinize the glacial-interglacial 17O-excess amplitude shift around 400,000 years ago, with amplification of variations in the most recent part, with lower minima, while maxima reach similar levels. This shift could have emerged after the Mid-Pleistocene Transition.

How to cite: Samin, E., Landais, A., Combacal, T., Grisart, A., Jouzel, J., Masson-Delmotte, V., Minster, B., Prié, F., and Stenni, B.: First 17O-excess record for the EPICA Dome C deep ice core, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11227, https://doi.org/10.5194/egusphere-egu25-11227, 2025.