Robotic Exploration of Underwater Glacial Walls

December 21, 2022

Jackson School Professor Partners with Keck Foundation to Lead Voyage into Uncharted Waters

It’s the front line of climate change and could hold the key to predicting global sea level rise, but what goes on at the underwater face of Greenland’s glaciers is a mystery to science.

That could change in 2023 with a bold new mission led by researchers at the Jackson School of Geosciences that will explore three of Greenland’s glaciers with a submersible robot. The voyage will be the first time Greenland’s glaciers — which make up the world’s second-largest ice sheet — will be seen up close underwater.

The mission is made possible by funding from the W.M. Keck Foundation, one of the nation’s largest philanthropic organizations, and Nereid Under Ice (NUI), a remotely operated vehicle that’s engineered to survive ice-covered seas by project partner the Woods Hole Oceanographic Institution (WHOI). NUI will brave icebergs and riptides to approach within feet of the glaciers and return with data and samples from their underwater environment.

The scientists’ primary focus is not glacial ice, but the natural sand walls — or moraines — that buttress the glaciers and are thought to naturally, but precariously, stabilize the ice sheet. What they learn will reveal what’s shoring up glaciers across the entire Greenland ice sheet, which could lead to more accurate model projections for future sea level rise.

“The big uncertainty in Greenland’s contribution to sea level rise is how fast the ice sheet is going to lose mass,” said Jackson School Professor Ginny Catania, who is leading the voyage. “We know how much sea level is stored in the ice sheet, we know climate is warming and changing the ice sheet, but what we don’t know is the rate at which these glaciers will contribute to sea level rise.”

NUI will make its way underwater to three glaciers, mapping the seafloor topography as it goes. Once at its target site, operators aboard a nearby support ship will remotely guide the robot’s manipulator arm to retrieve sediment cores from the glacier’s moraines. The vehicle will also gather samples from the massive sediment plumes jetting from under the glaciers.

According to WHOI engineers, the robot has layers of built-in redundancy, including multiple thrusters, battery packs and navigation systems to allow it to operate in difficult conditions far from its support ship.

Despite the precautions, the hazardous ocean conditions mean the mission will face significant challenges. That’s why Catania approached the Keck Foundation, which is known for supporting high risk, high-reward science.

According to Demian Saffer, director of the University of Texas Institute for Geophysics (UTIG), where Catania also works, the project is exactly the kind of bold step needed to tackle questions about climate change and geohazards.

“If it succeeds, it could transform our understanding of sea level rise,” he said.

The mission will investigate glaciers in Western Greenland that lie in the path of warming Atlantic waters but have responded to climate change in different ways. Since 2000, glacier Kangilliup Sermia has experienced only minor retreat, Umiammakku Sermiat glacier retreated rapidly before stabilizing again in 2009, and Kangerlussuup Sermia glacier has remained largely unaffected by warming.

“They provide a nice test case for ideas about what’s building the moraines and how those processes may vary between location,” Catania said.

The information could also be crucial for future geoengineering projects. Some scientists have suggested building artificial moraines as a way of buying time while the world transitions to low-carbon energy sources. The voyage is scheduled for midsummer 2023. Partner institutions include the University of Idaho, the University of Florida and UTIG.