AUV 'Ran' Vanished Under Antarctic Ice After Mapping Terraced, Grooved Underside of Dotson Ice Shelf
Mission Overview
In 2022, the autonomous underwater vehicle (AUV) Ran, operated by researchers from the International Thwaites Glacier Collaboration (ITGC), conducted a survey beneath the Dotson Ice Shelf in West Antarctica. The team returned in early 2024 to observe changes in the ice, but the vehicle did not resurface and was subsequently lost.
Mapping Results
During its 2022 mission, the 20-foot bright orange AUV Ran used upward-looking sonar to map the underside of the ice shelf. Over 27 days, the vehicle traveled more than 1,000 kilometers (approximately 620 miles).
It captured high-resolution sonar images of over 140 square kilometers (approximately 54 square miles) of sub-ice terrain.
The survey revealed that the ice was not smooth. Instead, it featured terraces, channels, grooves, and teardrop-shaped pits, some nearly 1,000 feet long. These features were not visible from satellite imagery.
Research Context
The mapping mission was part of the International Thwaites Glacier Collaboration (ITGC). The research team was led by oceanographer Anna Wåhlin of the University of Gothenburg.
The West Antarctic Ice Sheet’s stability is subject to observation by scientists studying the impact of ocean currents carrying heat into cavities beneath ice shelves. AUVs are used to study these sub-ice environments, which are otherwise inaccessible.