A look back at the Under Antarctica expedition | Adventure and Discovery Festival

South Pole On Inaccessibility

After a 42-day expedition and having covered nearly 1,800 km since setting off on 3 November 2025, Heïdi Sevestre and Matthieu Tordeur have reached the South Pole of Inaccessibility, one of the most isolated places on the planet and the point in Antarctica furthest from any coastline.

This arrival marks a major milestone in the Under Antarctica expedition. Itis the fifth expedition worldwide and the first French one to reach this site by kite-skiing. To our knowledge, Heïdi Sevestre has also become the first woman to reach the Soviet South Pole of Inaccessibility using this method of travel. The last human presence at this site was in 2023, via aeroplane.

Once there, the scientists were able to deploy their radar around the former Soviet station, now buried under the ice, in order to gain a better understanding of what lies beneath the surface of the ice cap.This represents a valuable advance for polar research and our understanding of glacial dynamics.

South Pole Geographical

After reaching the geographic South Pole,the legendary point marking the Earth’s axis of rotation, Heïdi Sevestre and Matthieu Tordeur continued their journey across the Antarctic continent. Once there, they carried out further scientific measurements before setting off on the final leg of the expedition, heading for Hercules Inlet, the end point of their crossing.

On this final stretch, conditions proved particularly challenging: heavily overcast skies, difficulties in recharging the scientific batteries and, at times, interrupted communications. Despite these challenges, the team was able to redeploy the deep-penetrating radar to a depth of 110 metres in orderto image the inner layers of the ice and map the bedrock beneath the Antarctic ice sheet.

Finish line Hercules Inlet

After reaching the geographic South Pole, Heïdi Sevestre and Matthieu Tordeur began the final stage of their crossing. Conditions became harsher: strong winds, a very compact ice surface and a gruelling trek right up to the final kilometres. On several occasions, they had to adjust their progress, even finding themselves stuck inside their tent whilst waiting for the weather to ease.

As they approached the Antarctic coast, the Ellsworth Mountains appeared on the horizon, signalling the imminent end of the expedition. The arrival at Hercules Inlet, on the Filchner-Ronne Ice Shelf, proved tricky due to the numerous crevasses. On the day of their arrival, despite extreme vigilance and unpredictable winds, the two explorers covered the final kilometres on skis, pulling their pulkas.

On 21 January 2026 at 8.50 pm (French time), after an 80-day expedition and a journey of 4,000 km, they reached Hercules Inlet. ‘Under Antarctica’ becomes the first French crossing of the Antarctic interior by kite-ski and the first kite-ski expedition in the service of polar science.