Ice containing crucial information about Earth’s past climate over 1.2 million years has been reached in Antarctica, pushing back the previous record by 400,000 years, the European research team announced on Thursday.
“An international team of scientists has successfully drilled a 2,800 meter long ice core, reaching the rocky ground beneath the Antarctic ice sheet,” announced the “Beyond EPICA-Oldest Ice” program, a consortium of twelve European scientific institutions which welcome a “historic achievement”.
“The samples collected will make it possible to reconstruct, for the first time, important parameters of the Earth’s climate and the composition of its atmosphere beyond 800,000 years in the past”, the previous record established in 2024 by the same project, welcome the CNRS and the French Polar Institute, members of the consortium.
“According to the first analysis results, this layer of ice would provide a continuous climate record of at least 1.2 million years,” the two institutes welcome in a press release.
And potentially beyond: “although it has a priori lost part of its paleoclimatic information, the samples from the deepest 200 meters are likely to contain ice dating back several million years,” the press release continues.
However, additional analyzes are necessary to determine whether this ice is usable, once brought back to Europe by boat, stored at -50°C.
-“This is the longest continuous record of our past climate from an ice core, and it may reveal the link between the carbon cycle and our planet’s temperature,” said Professor Carlo Barbante of the Italian Polar Institute, coordinator of the exploration campaign.
Each meter of compressed ice records climatic data (temperatures, CO2 concentration, etc.) for a period of up to 13,000 years.
“The 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 go from 41,000 years to 100,000 years”, potentially under the effect of variations in the concentration of CO2 in the atmosphere, continues the press release.
It took scientists “more than 200 days of drilling operations and processing ice cores” over four austral summers in a row “in the harsh environment of the central Antarctic plateau, 3,200 meters above sea level.” altitude and under an average summer temperature of -35°C,” explains another press release from the consortium.
“Dating of the underlying rocks will be undertaken to determine when this region of Antarctica was last ice-free,” it added.
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