Raising the Foro Drill in Allan Hills, Antarctica, 2022-2023. (Photo: Julia Marks Peterson/COLDEX)
A team of U.S. scientists working with the Center for Oldest Ice Exploration (COLDEX) have discovered the world’s oldest directly dated ice and air. Unearthed in the Allan Hills region of East Antarctica, the ice and the air bubbles trapped within date back an astonishing 6 million years, according to a study published last month in the Proceedings of the National Academy of Sciences. This landmark find doesn’t just surpass previous ice samples by over 3 million years, per the research team, but it also offers critical information about the Earth’s geological history.
“Ice cores are like time machines that let scientists take a look at what our planet was like in the past,” Sarah Shackleton, lead author and a scientist at Princeton’s Woods Hole Oceanographic Institution, remarked in a statement released by Oregon State University (OSU). “The Allan Hills cores help us travel much further back than we imagined possible.”
To date the sample, researchers tapped the air bubbles within the ice and carefully measured the radioactive decay in their argon isotopes. The team then analyzed oxygen isotopes within the ice core, allowing them to determine that the Allan Hills region had experienced a long-term cooling of about 22°F during the Pliocene era. By investigating these ice cores, scientists can glean insights into the levels of atmospheric greenhouse gases and ocean heat content throughout ancient history. In turn, such research can inform our contemporary understanding of natural climate change.
“We knew the ice was old in this region,” Ed Brook, COLDEX director and a paleoclimatologist at OSU, added. “Initially, we had hoped to find ice up to 3 million years old, or maybe a little older, but this discovery has far exceeded our expectations.”
Amid further research into the collected sample, a COLDEX team will return to Allan Hill in order to drill more cores—and hopefully find more ancient ice.
“Given the spectacularly old ice we have discovered at Allan Hills, we also have designed a comprehensive longer-term new study of this region to try to extend the records even further in time, which we hope to conduct between 2026 and 2031,” Brook explained.
To learn more about the team’s research and its impact, explore the full study in the Proceedings of the National Academy of Sciences.
A team of U.S. scientists have unearthed the world’s oldest ice in the Allan Hill region in East Antarctica.
Allan Hills, 2022-2023. (Photo: Julia Marks Peterson/COLDEX)
The ancient ice and the air bubbles trapped within it date back 6 million years, offering critical insight into Earth’s geological history.
A core of 6 million-year-old Antarctic ice. (Courtesy COLDEX)
All images via OSU’s press room.
Sources: Scientists discover oldest air on record trapped in 6-million-year-old Antarctic ice; Six-million-year-old ice discovered in Antarctica offers unprecedented window into a warmer Earth; 6 million-year-old ice discovered in Antarctica shatters records — and there’s ancient air trapped inside
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