On Monday evening, glaciologist Dr. Heïdi Sevestre spoke at The University Centre in Svalbard (UNIS) in Longyearbyen, reflecting on the Under Antarctica Expedition she completed earlier this year with explorer Matthieu Tordeur.
In a previous article for Polar Journal, the expedition was presented as a proof of concept: crossing nearly 4,000 kilometers of Antarctica by kite-ski while collecting radar data. In Longyearbyen, Sevestre focused on what that looked like in practice.
Although she has extensive field experience in polar regions, kite-skiing was new to her. Training in northern Norway was followed by two expeditions across Greenland with Tordeur. On the first, scientific measurements only happened in camp. On the second, they began towing a radar system while moving, despite difficult conditions with rain on the ice sheet. At times they travelled at night when conditions were better.
“That was terrifying,” Sevestre said. “I would not do that again.”
Antarctica brought different constraints. After travelling from South Africa to their starting point inland, they began pulling pulkas weighing up to 250 kilograms each. The first ten days passed with almost no progress, as the wind did not allow them to move in the right direction.
“The first night in the tent is always a little bit brutal,” she said, describing temperatures around -28°C.
Once underway, progress depended on wind and terrain. Sastrugi made travel uneven and physically demanding, increasing the risk of falls while attached to the kite.
“Antarctica never lets you have too much fun,” Sevestre said.
The expedition included two ground-penetrating radar systems, but the longer system was packed away for most of the journey and only used later in the expedition when conditions allowed.
Keeping equipment running in the cold became part of the routine. Batteries required “battery CPR” each evening, with two to three hours of warming before they would charge. Communication devices, which had worked in Greenland, failed due to the cold, leaving hand signals as the only reliable way to coordinate. Even the kite release systems remained frozen.
Out on the ice, options were limited. The surface made aircraft landings impossible, and outside assistance was not something they could rely on.
“We didn’t have any other choices but to keep going,” she said.
The expedition was shaped by different priorities. Tordeur focused on covering distance, while Sevestre emphasized safety and scientific measurements.
“Science slows you down. Sometimes science wins, sometimes speed wins.”
They managed this through regular check-ins.
“Every day there were many problems,” Sevestre said. “You have to focus on solutions.”
A key source of motivation came from the expedition’s educational outreach. Through a partnership with UNESCO and the Decade of Action for Cryospheric Sciences, with material developed by Témoins Polaires, more than 300,000 schoolchildren from 43 countries followed the journey. Paco, a small stuffed penguin, travelled with them, and they regularly spoke live with classrooms.
“That really keeps you going,” Sevestre said. “You remember that many people depend on what you’re doing. And that it’s a privilege.”
After around 60 days, they reached the geographic South Pole, where a short stop allowed for rest and repairs. With more than 1,000 kilometers still ahead, they left while conditions were still good.
By the end of the traverse, Sevestre and Tordeur had completed something that had not previously been attempted: crossing Antarctica by kite-ski while collecting scientific data along the way. The expedition shows that this approach is possible, but also what it requires. Movement depends on wind, progress is not consistent, and scientific work has to adapt to conditions on the ice.
Sevestre is now processing the radar data before handing it over to collaborating scientists. Asked whether she would do it again, she emphasized that the experience had given her confidence and shown what is possible, but also that recovery takes time.
Léa Zinsli, PolarJournal