Photo Story

Photos: First-ever underwater robotic mission to Greenland glaciers

The robotic submersible Nereid Under Ice (NUI) will collect data on the glaciers.

Published: Aug 01, 2024 10:50 AM EST

Mrigakshi Dixit

a month ago

Depiction of Nereid Under Ice (NUI)

WHOI/Casey Machado

A team of scientists, led by the University of Texas at Austin, is conducting a daring mission to explore the underwater edges of Greenland’s colossal glaciers.

This is said to be the “first-ever underwater exploration of three of Greenland’s glaciers.”

During this four-week expedition, the international team of experts will deploy a state-of-the-art robotic submersible to gather vital data about these icy giants.

“This is a big mission to try to capture as much information about how the glaciers behave underwater with these really sophisticated tools that we haven’t been able to use in the past,” said Ginny Catania, the expedition’s chief scientist and a research professor at the University of Texas.

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Robot submersible Nereid Under Ice
The robotic submersible Nereid Under Ice (NUI) will collect data on the glaciers. The Woods Hole Oceanographic Institution developed and manages the NUI. The submersible is engineered to operate safely in the perilous icy environment of the glacial fjord, which is basically a long, narrow inlet formed by glacial erosion. Fjords are formed when glaciers retreat and meltwater fills their U-shaped valleys. (Image: Luis Lamar/Avatar Alliance Foundation)
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Detailed images of seabed
The NUI submarine can capture detailed images of the seabed using optical cameras and multibeam sonar. The developers have also added Doppler current profilers, chirp sonar, and other sensors to its equipment. Moreover, the robot sub will be able to collect physical samples using its high-tech arm. The submersible will collect data on sediments exiting from beneath the ice and perform detailed, close-up geophysical studies of the ice and seabed. By analyzing sediment cores, researchers will reconstruct past climate impacts on glaciers. (Image: Christopher German)
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XOcean drone
In addition to the submarine data, the team will utilize an XOcean sea surface drone and equipment on the Marine Institute of Ireland's RV Celtic Explorer. Aerial drones will provide further insights from the glacier's surface. (Image: Marcy Davis/University of Texas Institute for Geophysics)
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Role of sediments
There's a diverse response to climate change among Greenland's outlet glaciers, with some retreating and others remaining unaffected. Determining the impact of sediments on glacial melt is one of the primary research objectives. “Most of the ice sheet has retreated, but there are a few glaciers that have not retreated next to glaciers that have retreated a lot. And it could be because sediments are stabilizing the glaciers,” Catania said. (Image: Denis Felikson)
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Underwater barriers
Scientists believe that glaciers are shielded from warm ocean waters by underwater barriers called moraines. These moraines are formed by sediment carried beneath the glacier and deposited at its edge. “These buttressing walls also form when glaciers advance, bulldozing the seafloor ahead of them,” the press release noted. To accurately forecast the future of the Greenland and Antarctic ice sheets, researchers need to determine how well these sediment walls slow melting, how quickly they form, and how long they last.
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Greenland ice calving
Greenland's ice sheet is known to be melting at an accelerating rate. The ice sheet holds enough ice to raise sea levels by 23 feet (7 meters). By studying the sediments and the structure of these underwater giants, scientists hope to unlock the mysteries of glacial melt and its impact on sea level rise. “What the expedition reveals about future sea level rise will be vital for coastal communities around the world,” added Catania. (Image: ESA)
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Expedition aboard RV Celtic Explorer
The vessel carries a 24-member team representing seven institutions, with a broad range of expertise including sedimentology, glaciology, oceanography, marine geophysics, and computational modeling, to ensure comprehensive scientific exploration. (Image: Sean Gulick/Jackson School of Geosciences)