VUB and ULB Scientists Return from Antarctica with Clues to Million-Year-Old Ice
At the end of 2024, researchers from the Vrije Universiteit Brussel (VUB) and the Université libre de Bruxelles (ULB) spent several weeks in Antarctica in search of million-year-old ice. During the expedition, they collected fifteen shallow ice cores and over a thousand surface ice samples. These are now being shipped to Belgium, where they will be analysed in the laboratories of the participating universities.
They drilled shallow ice cores to determine the surface age of the ice, collected surface ice samples, placed stakes to measure surface ice loss, and gathered radar data to assess ice thickness. The data will help scientists identify where the oldest ice can be found and where to drill in the search for million-year-old ice.
“Air bubbles trapped in the ice can tell us how the composition of the atmosphere varied in the past, and therefore what the climate looked like hundreds of thousands — or even a million — years ago”
“Antarctica is covered by an ice sheet in most places, and the deeper you go into it, the older the ice becomes,” explains Prof. Harry Zekollari. “Air bubbles trapped in the ice—formed when snow fell on the surface and gradually turned to ice—can tell us how the composition of the atmosphere changed over time, and therefore what the climate looked like hundreds of thousands, or even a million, years ago.”
Some of the oldest ice in Antarctica lies at the base of the ice sheet, where it meets the bedrock of the Antarctic continent. Previous international scientific expeditions to drill deep ice cores in the search for ancient ice have yielded climate data going back several hundred thousand years. As part of the EPICA project (European Project for Ice Coring in Antarctica), scientists retrieved an ice core dating back 800,000 years near Dome C, one of the highest points of the Antarctic ice sheet. More recently, in a follow-up project (Beyond EPICA), ice over 1.2 million years old was discovered.
Many of these projects involve drilling vertically several kilometres deep into the ice—an extremely complex, costly and time-consuming method.
Blue ice areas
“With the FROID project, we’re taking a different approach to finding very old ice—one that doesn’t involve drilling ice cores several kilometres deep,” says Dr Veronica Tollenaar. “We’re focusing on blue ice areas on the continent. The Antarctic ice sheet slowly flows from the interior towards the coast under the force of gravity. As the ice approaches the mountains, blue ice areas cause the deepest, oldest layers of the ice sheet to be pushed to the surface, making them more accessible.”
During the expedition, the team collected a total of fifteen shallow ice cores, more than a thousand surface ice samples, and carried out 200 kilometres of radar transects. The ice samples are currently being shipped to Belgium, where they will be analysed in the laboratories of the participating universities.
A rare phenomenon
“With the FROID project, we’re taking a different approach to finding very old ice—one that doesn’t involve drilling ice cores several kilometres deep,” says Dr Veronica Tollenaar. “We’re focusing on blue ice areas on the continent. The Antarctic ice sheet slowly flows from the interior towards the coast under the force of gravity. As the ice approaches the mountains, blue ice areas cause the deepest, oldest layers of the ice sheet to be pushed to the surface, making them more accessible.”
During the expedition, the team collected a total of fifteen shallow ice cores, more than a thousand surface ice samples, and carried out 200 kilometres of radar transects. The ice samples are currently being shipped to Belgium, where they will be analysed in the laboratories of the participating universities.
Unexpected visitors
Just before the New Year, the team had an unexpected encounter. “On New Year’s Eve, we were visited by a few south polar skuas—large seabirds that usually live along the coast,” says Dr Etienne Legrain. “Henri Robert, the science coordinator at IPF and also a biologist, told us it’s not unusual for skuas to fly hundreds of kilometres to breed in small numbers in the Sør Rondane Mountains, but after so many days in the field, we were still surprised to see any sign of life.”
The researchers behind the FROID project plan to return to Antarctica for a second field campaign during the 2026–27 research season. Their expedition was funded by the Belgian Federal Science Policy Office (BELSPO) and the QUOI project at the Université libre de Bruxelles, with strong logistical support from the International Polar Foundation (IPF), which operates the zero-emission Princess Elisabeth Antarctica research station on behalf of the Belgian Polar Secretariat.
About the Expedition and the FROID Project
A team of scientists from the FROID project (Finding the world’s oldest ice record around the Princess Elisabeth Station) spent several weeks in December and early January at the Nils Larsen Blue Ice Field, near the Sør Rondane Mountains, for a field expedition. Four researchers from the Vrije Universiteit Brussel (VUB)—Maaike Izeboud, Etienne Legrain (VUB/ULB), Veronica Tollenaar, and Harry Zekollari—ventured into the mountains, supported by field guide François Pallandre and technician Nicolas Grosrenaud from the International Polar Foundation (IPF).
The FROID project is funded by the Belgian Federal Science Policy Office (BELSPO).
Read the interview with Harry Zekollari
Professor Harry Zekollari and his team of glaciologists are studying how rapidly the world’s glaciers are disappearing. With support from European and Flemish research funds, they are refining models that help us understand—and predict—the pace of this melting.
