Unmanned submarine mapping West Antarctica’s Dotson Ice Shelf reported strange under-ice structures, then went silent after traveling underwater roughly ten miles towards the ice shelf’s center.

An autonomous underwater vehicle, Ran, mapping beneath Antarctica’s Dotson Ice Shelf, reported discovering unusual under-ice structures before losing contact with its operators, raising concerns about ice melt processes and glacier stability.

Ran, an unmanned robotic submarine, spent weeks exploring the underside of Dotson Ice Shelf, covering approximately fifty square miles. During its mission, it mapped features such as terraces, pits, fractures, and channels—many of which had not been visible in satellite imagery. The vehicle reported encountering strange formations, including teardrop-shaped pits and terraced ice surfaces, before suddenly going silent after traveling roughly ten miles into the cavity.

Researchers led by Professor Anna Wåhlin of the University of Gothenburg, who coordinated the mission, confirmed that Ran’s disappearance occurred after the vehicle completed its mapping, with no signals received upon its return. The team is investigating whether mechanical failure, collision, or other factors caused the loss of contact. The earlier missions provided valuable data on how warm deep water influences melting patterns beneath Dotson, revealing that erosion is focused on the western side where warmer currents are more active.

Why It Matters

This event is significant because understanding melt processes beneath ice shelves like Dotson is crucial for predicting future sea level rise. The discovery of unusual structures and the subsequent loss of the vehicle highlight gaps in current models of ice-ocean interactions. Since ice shelves act as buttresses for land glaciers, their destabilization could accelerate glacier flow into the ocean, contributing to sea level rise.

Background

Dotson Ice Shelf is part of West Antarctica, an area contributing significantly to global sea level rise due to ice loss. Previous satellite studies have shown that warm Circumpolar Deep Water melts ice shelves from below, thinning them over time. The 2022 missions by Ran built on earlier efforts to understand the complex basal processes, revealing detailed features beneath the ice that are not detectable via satellite. The recent loss of the vehicle underscores the challenges of remote exploration in such harsh environments.

“Seeing Ran disappear into the dark, unknown depths is daunting, but the data we collected has already transformed our understanding of ice-ocean interactions.”

— Anna Wåhlin

“The strange formations we observed suggest complex melt patterns that are not yet fully understood and could influence how we model ice shelf stability.”

— Unspecified team member

What Remains Unclear

It remains unclear what caused Ran to go silent—whether mechanical failure, collision with ice ridges, or other factors. The exact nature of the strange structures reported by Ran is also still under investigation, and further analysis is needed to determine their significance for ice melt processes.

What’s Next

The research team plans to conduct further investigations, including deploying additional autonomous vehicles and analyzing the collected data. Efforts are underway to recover or locate Ran if possible, and to incorporate these findings into improved models of ice shelf melting and glacier response.

Key Questions

What is the significance of the strange structures reported by Ran?

The structures suggest complex melting patterns and basal processes that are not visible from satellite data, which could influence how ice shelves weaken and disintegrate over time.

What caused Ran to go silent?

It is not yet known; possibilities include mechanical failure, collision, or other technical issues. The team is investigating the cause.

How does this event impact predictions of sea level rise?

Understanding basal melt processes and ice shelf stability is critical for accurate sea level rise projections. The new data could lead to improved models, but the loss of Ran highlights the challenges of remote sensing in these environments.

Will the findings from Ran’s mission be used in future research?

Yes, the detailed maps and data will inform future studies of ice-ocean interactions and may guide new missions to explore these environments further.