On the Petit Dôme C site in Antarctica, a research team representing twelve institutions from ten European nations
has just achieved a major objective in climate sciences: it successfully led a drilling campaign to reach the subglacial continent at a depth of 2800 meters. According to the first analysis results, this layer of ice would provide a continuous climate record of at least 1.2 million years. This is the longest continuous climate record from ice cores, surpassing the previous record of 800,000 years held by the EPICA project following the 2004 drilling campaign at Dome C.
However, additional analyzes remain necessary to determine whether even older ice is exploitable. Although it has apparently lost part of its paleoclimatic information, samples from the deepest 200 meters are likely to contain ice dating back several million years.
Study the ice in depth to go back in time
Ice extracted during this fourth campaign beginning in November 2024 has preserved a record of Earth’s climate history, providing direct insight into atmospheric temperatures and greenhouse gas concentrations over the past 1.2 million years.
« Thanks to the isotope analysis system prepared for the field and managed by Amaëlle Landais, CNRS researcher at the Climate and Environmental Sciences Laboratory, we are able to see almost in real time during drilling the succession of glacial cycles – interglacials recorded in the ice and thus confirm the preliminary dating. » explains Frédéric Parrenin, CNRS researcher at the Institute of Environmental Geosciences.
Once returned to Europe, the ice cores will be analyzed with the aim of reconstructing the climatic history of the Earth and the composition of its atmosphere during this long period up to our era.
More particularly, these analyzes should help elucidate the reasons for the mysterious transition that occurred during the mid-Pleistocene, a period between 900,000 years and 1.2 million years in the past, during which glacial cycles saw their amplitude increase and their period goes from 41,000 years to 100,000 years. In fact, only polar ice makes it possible to reconstruct CO concentrations.2 reliably, a gas that is suspected of having played a determining role in this transition. Additionally, Earth’s magnetic field reversed and collapsed several times during this period, and scientists hope these events will have been recorded in the ice.
Scientists also hope to be able to extract rocks from beneath the ice, the analysis of which could indicate when the continent was last deglaciated. This pharaonic project will end in May 2026.
A European collaboration
The project was funded by the European Union and supported by national funding agencies, such as the ANR in France which funded the Towards Beyond EPICA (ToBE) project.
Frédéric Parrenin, CNRS research director at the Institute of Environmental Geosciences (CNRS/Université Grenoble Alpes/INRAE/IRD) coordinates the French part of “Beyond EPICA – Oldest Ice”, in collaboration with project coordinator Carlo Barbante, professor at the University of Venice. From the same laboratory, Catherine Ritz, CNRS research director, coordinated the site search and Olivier Alemany, CNRS research engineer, specialized in glacial drilling techniques and responsible for the French Glacial Drilling Platform (F2G), there participated with his team.
In France, four laboratories managed by the CNRS and its partners are involved in this project alongside the French Polar Institute:
-
the Institute of Environmental Geosciences (CNRS/Université Grenoble Alpes/INRAE/IRD),
-
the Climate and Environmental Sciences Laboratory (IPSL
CEA/CNRS/University Versailles Saint-Quentin-en-Yvelines), -
the Environmental Geosciences Research and Teaching Center (Aix-Marseille University/CNRS/INRAE/IRD) and
-
the Petrographic and Geochemical Research Center (CNRS/University of Lorraine)
David Renault, scientific director of the French Polar Institute, emphasizes that this project was the subject of technical development and specific logistical knowledge to enable the establishment and operation of the isolated camp of Little Dome C. The camp was in fact deployed and maintained thanks to the proximity of the Concordia station managed jointly by the French Polar Institute and ENEA
. The organizations integrated the operation of the Beyond EPICA camp into the annual operation of Concordia which involved, in addition to specific knowledge of the Antarctic environment, very important means of transport: planes from the Italian Mario Zucchelli Antarctic station for people , the raid between Dumont d’Urville and Concordia to transport heavy loads, and the French and Italian ships, theAstrolabe and the Laura Bassi for travel and freight, a colossal logistical challenge renewed every year since December 2020.
In addition, fifteen thesis scholarships were funded by the European Union through the International Training Network DEEPICE, coordinated in France by Amaëlle Landais, CNRS researcher at the Climate and Environmental Sciences Laboratory and Emilie Capron, CNRS researcher at the Institute of Environmental Geosciences. Three thesis students participated in this fourth drilling campaign.
To learn more about “Beyond EPICA – Oldest Ice”: www.beyondepica.eu
Photos and videos of field campaigns available on request.
About the CNRS:
A major player in fundamental research on a global scale, the National Center for Scientific Research (CNRS) is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to combine different scientific disciplines to illuminate and understand the challenges of the contemporary world, in conjunction with public and socio-economic stakeholders. Together, sciences serve sustainable progress that benefits all of society. (www.cnrs.fr)
About the French Polar Institute:
The French Polar Institute organizes scientific expeditions to the Antarctic, the Arctic and the Subantarctic Islands to deploy science in these extreme environments. It employs personnel from several trades to maintain polar stations and ensures their transportation as well as that of scientists and necessary equipment in the field. Other additional missions are entrusted to the French Polar Institute such as the dissemination of scientific knowledge linked to the polar worlds, the selection of deployed scientific projects and national and international representation. (institut-polaire.fr)
Related News :