Researchers at the University of Gothenburg will acquire a new state-of-the-art autonomous underwater vehicle (AUV) to continue critical research in Antarctica. The new submarine, named Ran II, replaces its predecessor, Ran, which was lost in January 2024 during a pioneering mission beneath the Thwaites Glacier. The purchase is made possible by a significant donation from the Voice of the Ocean Foundation combined with insurance funds, allowing scientists to plan future expeditions to the world’s most remote marine environments.
The original Ran AUV was instrumental in advancing the understanding of glacier dynamics, providing the first-ever close-up observations from beneath the massive Thwaites Glacier, often called the “Doomsday Glacier.” For six years, the vehicle gathered unprecedented data on the mechanisms causing ice to melt, challenging previous assumptions based on satellite data alone. The successor vessel, Ran II, is expected to be delivered in the winter of 2026/2027 and will feature upgraded technology to enhance both safety and the precision of its measurements in hazardous under-ice conditions.
Pioneering Research Under the Ice
The first Ran submarine was a unique platform that allowed scientists to venture into one of Earth’s most inaccessible locations: the grounding zone of a major glacier. In 2019, it became the first AUV to navigate beneath the Thwaites Glacier, a massive and rapidly melting ice shelf in West Antarctica. This work was led by Anna Wåhlin, a professor of oceanography at the University of Gothenburg, who explained that the vehicle provided groundbreaking images and data from the underside of the ice. This allowed researchers to observe the exact mechanisms of melting, which satellite data can only suggest.
During its years of operation, Ran also completed the first full-scale mapping of the underside of a glacier in 2022. This survey revealed previously unknown structures and pointed to complex melting processes occurring deep beneath the ice, opening an entirely new field of interdisciplinary research. The data collected by Ran on warm water inflows and ice dynamics has been invaluable to the international research community studying climate change and sea-level rise. Despite the known risks of operating in such a dangerous environment, Professor Wåhlin noted that losing the AUV during a mission was a better fate than letting it sit unused.
The Loss of a Key Instrument
In January 2024, during an expedition under the Thwaites Glacier, the original Ran AUV was lost. Missions in these under-ice environments are inherently risky due to the complex and unpredictable terrain, including deep channels and shifting ice formations. The loss of the submarine was a significant setback for the research team and for polar science, as Ran was one of only three AUVs of its type in the world when it was commissioned in 2018.
The vehicle’s disappearance highlighted the extreme dangers involved in gathering direct measurements from the front lines of climate change. These high-risk, high-reward missions are essential for improving climate models and predicting future sea-level rise. The loss prompted an immediate effort to secure a replacement to avoid a long-term gap in data collection from this critical region.
Introducing the Next Generation AUV
The new vehicle, Ran II, is being constructed by the Norwegian company Kongsberg AS, a leader in marine technology. It is scheduled for delivery in the winter of 2026/2027. While the new AUV will have the same fundamental capacity as its predecessor, it will incorporate significant technological advancements to improve performance and safety.
Enhanced Navigation and Safety
Ran II will be equipped with more robust decision-support systems for emergencies and improved navigation capabilities. These upgrades are designed to increase both safety and precision while operating in challenging environments, such as near the seabed or beneath glaciers and sea ice. The new systems will leverage advances in artificial intelligence for mission planning, navigation, and environmental monitoring, reducing the risk of another loss.
Advanced Sensor Technology
The new submarine will feature a suite of sophisticated sensors capable of taking simultaneous, high-resolution measurements. It will be rated to a depth of 3,000 meters and will use multibeam echo sounders to map underwater topography with high precision. These instruments will also measure ocean currents and water chemistry, providing a comprehensive picture of the subglacial environment.
Future Missions and Collaborations
With Ran II, the University of Gothenburg will resume its vital research exploring the hidden frontiers beneath Antarctica’s ice sheets. The acquisition was made possible through a collaboration between the university, its insurance provider, and a major donation from the Voice of the Ocean Foundation. This partnership will not only enable continued polar research but also expand the AUV’s use to other regions.
The collaboration with the Voice of the Ocean Foundation will give researchers the opportunity to deploy Ran II in waters closer to home, such as the Baltic Sea. Sanna Thimmig Johansen, the foundation’s CEO, stated that the project will deepen the understanding of ocean changes and strengthen Sweden’s leading role in marine science. This initiative aims to accelerate research by providing scientists with access to advanced autonomous platforms and the high-resolution data they can collect.
