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Researchers discovered extreme hot springs under the Arctic ­

Their discoveries could be crucial for the search for life in our Solar System.

The study’s two senior authors, Reeves and Jamieson, together on the sea ice at Aurora in 2021.
Amanda Schei COMMUNICATIONS ADVISER
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Many kilometres down on the seafloor in the Arctic, beneath thick, drifting sea ice – where no sunlight can reach – life flourishes against all odds. But why?

Down there, hydrothermal vents – hot springs on the seafloor where superheated, mineral-rich water seeps out – sustain unique oasis-like ecosystems that survive on chemical energy contained in the hot waters.

Over recent decades, deep-sea researchers have collected samples from vents across the globe. But since the early 2000s, one particular group of vents beneath polar ice has remained a 'last frontier' in deep-sea exploration.

For more than 20 years, researchers have known that along Earth's slowest-spreading mountain chain, the Gakkel Ridge, there is at least one vent site where ‘Aurora’ might be located. 

But thick, drifting sea ice has created enormous technical challenges and significant risks in reaching the site. If an underwater robot were to get stuck or trapped, the entire mission could be lost.

In 2021, an international research team finally succeeded in this ‘moon landing’. The samples have now been analysed, and the first research findings are ready.

A significant scientific and technological feat under the ice

“It felt like landing on the Moon. Honestly, I think we underestimated how difficult it was going to be. But we did it, and it was an incredible moment,” Eoghan P. Reeves says about the expedition.

He is a professor at the University of Bergen's Department of Earth Science & Centre for Deep Sea Research.

Reeves explains that this was one of the most demanding ocean research expeditions ever carried out. No one had done this before. The team was aboard the icebreaker Kronprins Haakon and used a remotely operated vehicle (ROV) to collect the very first mineral deposit and vent fluid samples from a hydrothermal vent field nearly four kilometres under moving, permanent sea ice.

“In the ship’s conference room, everyone watching the video feed from the seafloor was just cheering with joy when we got the first views of the black smoker. But for those of us guiding the ROV and pilots, it was almost panic at that moment: How on earth were we going to land this thing in the right place?” he recalls.

Here is the research vessel Kronprins Haakon, which was used for the expedition.

“I understood, in that moment, how stressed Neil Armstrong might have felt in the final minutes of Apollo 11. But we had done this in many cruises around the world, now we just had to keep calm, and work fast,” he says.

Spectacular black smoker ‘chimneys’ on the seafloor

The hydrothermal vents at Aurora look much like smoking chimneys, venting fluids close to 350ºC loaded with metals, sulphur, and gases. 

When these hot fluids meet the icy seawater, dissolved minerals precipitate out and build chimney-like structures on the ocean floor. Footage from this expedition were recently featured in the Netflix documentary series Our Oceans, narrated by Barack Obama.

These kinds of environments have long fascinated researchers, because they can tell us something about how life may have first emerged on Earth – and how, in the future, we might search for life on ice-covered ocean world moons such as Europa and Enceladus in our Solar System.

“There are many reasons why we study hydrothermal vents. Some people are interested in ore deposit formation: metals that could become important if deep-sea mining ever develops. Others, like me, are also interested in what they can tell us about the fundamental chemistry of life on Earth and maybe in our nearest neighbour worlds,” says Reeves.

Unexpected traces of nickel and cobalt

“When we got the first samples from Aurora, that was really the proof that we could actually do this kind of deep sea exploration. But afterwards, the real scientific work began, back in the labs. That’s where the new findings are created and tested,” says Reeves.

So what does the seabed under the Arctic ice actually look like?

The findings show that the hydrothermal vents in this area are different from vent systems elsewhere, and much more extreme than the well-known Loki’s Castle vents farther south in Norwegian waters.

“They are much, much hotter, and richer in many different chemicals,” says Reeves. “Just getting there to find familar chemicals would have been worth the feat, but we found brand new compositions that really expanded our menu of black smoker flavours.”

Chimney samples reveal unexpected traces of elements normally only find deep inside the Earth, such as nickel and cobalt.

Massive hydrogen release: ‘rocket fuel and candy’ for life

“We discovered chimneys that were unusually fragile and thin, with minerals we didn’t expect at all. The chemistry of the fluids was also special: they are extraordinarily rich in dissolved hydrogen gas,” Reeves explains.

In fact, hydrogen levels were over twice as high as at any other vent field studied so far.

Reeves describes hydrogen as ‘rocket fuel and candy for microbes.’ For microscopic life, such energy sources are worth gold in the barren desert of the deep sea. It’s energy they can thrive on.

The research team also found new biological species and unusual coatings on the minerals. Some of the structures were coated in calcium carbonate, unlike ordinary chimneys, almost like a protective film.

“We are seeing things there that don’t look like anything we’ve found before elsewhere. It means we need to rethink what we think is happening in these places, and, importantly, keep exploring down there,” says Reeves.

Reference:

Lapointe et al. The ice-covered Aurora hydrothermal vent field, Gakkel Ridge, Arctic Ocean: ultramafic-influenced venting at a mafic axial volcano on Earth’s slowest spreading center, Earth and Planetary Science Letters, vol. 672, 2025. DOI: 10.1016/j.epsl.2025.119696

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