Antarctic Team Drills 6 Million Years Into Earth’s Past

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AAt the end of the Earth, there is a kind of trace, preserved in layers of Antarctic ice – you could even call it the memory of our planet. Now scientists have discovered a new chapter in these prehistoric records.

By drilling into ancient glaciers in the Allan Hills region of southeast Antarctica, researchers from the Center for the Exploration of Oldest Ice (COLDEX) have recovered an ice core dating back 6 million years, more than twice as old as the oldest similar ice core on record.

In an article published in the Proceedings of the National Academy of SciencesThe COLDEX team said they determined the age of the core by analyzing levels of an isotope, argon-40, trapped in tiny pockets of air. For the first time, the researchers were also able to directly measure the region’s cooling over the past 6 million years. An analysis of oxygen isotopes in the frozen water showed that the area cooled by about 22 degrees Fahrenheit. While Antarctica was once covered in lush forests, the snapshot captured by the COLDEX ice core records the gradual cooling that occurred after the continent was covered in ice.

Read more: “The hidden landscape that holds back the sea”

Earlier this month, a team from the British Antarctic Survey announced the discovery of a 1.2 million-year-old ice core, the oldest continuous ice core recovered to date. COLDEX’s new discovery represents the oldest discontinuous ice core, or a core extracted from ice that has been disturbed by movement. The Alan Hills area, where the core was drilled, is an area where glacial ice uplift has pushed older ice closer to the surface, allowing studies to be carried out with relatively shallower drilling.

Both samples will provide researchers with invaluable data on how our planet has changed over millions of years and potentially help them glean clues about how our climate will change in the future.

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Main image: Liam Quinn / Wikimedia Commons

• Jake Currie

  Published on October 30, 2025

  Jake Currie is a writer based in Brooklyn, New York.