Cutting-Edge Submersible Explores Antarctica's Ice, Then Disappears

A pioneering mission led by scientists from the International Thwaites Glacier Collaboration (ITGC) utilized an autonomous underwater vehicle (AUV) named Ran to explore the uncharted depths beneath the Dotson Ice Shelf in West Antarctica, revealing critical insights into glacier dynamics and the effects of climate change. However, the mission took an unexpected turn when Ran mysteriously vanished, leaving researchers with both valuable data and unresolved questions.

The mission, which commenced in 2022, aimed to study the mechanisms contributing to the accelerated melting of Antarctica's ice shelves, particularly the Dotson Ice Shelf, a crucial stabilizing structure for glaciers. According to a report published in the journal *Science Advances* by Anna Wåhlin, a researcher at the University of Gothenburg and lead author of the study, the data collected by Ran significantly enhances the understanding of how glaciers interact with oceanic currents, which is vital in predicting future sea-level rise. Wåhlin stated, “By navigating the submersible into the cavity, we were able to get high-resolution maps of the ice underside. It’s a bit like seeing the back of the Moon.”

During its initial deployment, Ran traversed over 600 miles, mapping approximately 50 square miles of the ice shelf. The AUV employed advanced sonar technology, capturing detailed images of the underside of the ice. The findings revealed previously unknown features beneath the shelf, including unique tear-drop shapes and complex erosion patterns that are critical for understanding the melting mechanisms at play.

Research indicates that the eastern section of the Dotson Ice Shelf, being thicker, melts at a slower rate compared to the western section. This disparity is believed to be influenced by a phenomenon known as modified Circumpolar Deep Water (mCDW), a mixture of warmer Pacific and Indian Ocean waters that interacts with the ice base, thereby accelerating melting. The data collected by Ran showed significant melting rates in the glacier's fractures, providing insights that could refine existing models of ice shelf dynamics.

Despite the success of the initial exploration, the second deployment in 2024 was marked by the disappearance of the AUV. Scientists suspect that Ran may have either become lodged on the ocean floor or been affected by local wildlife, such as seals, known to inhabit the region. Wåhlin expressed her disappointment over the loss but remained optimistic about the data already gathered. “Although we got valuable data back, we did not get all we had hoped for,” she remarked.

The unexpected loss of Ran poses a significant challenge to the research team, which now faces the task of continuing their investigation into the melting ice shelves without the AUV. Wåhlin emphasized the necessity of this research for understanding the future of Antarctica's ice sheet, stating, “This research is needed to understand the future of Antarctica’s ice sheet, and we hope to be able to replace Ran and continue this important work.”

As climate change continues to affect glacial dynamics, the insights gained from the Ran mission underscore the critical need for advanced technology in environmental research. The ongoing studies into the melting of the Dotson Ice Shelf will not only contribute to scientific knowledge but also inform policymakers about the potential implications of rising sea levels due to climate change. The ITGC remains committed to its research objectives, aiming to enhance understanding and foster solutions to the challenges presented by a warming planet.