Incredible 'black smokers' discovered in a part of the deep ocean where they should not exist

Water temperatures hovering just above freezing, fifteen-foot seas choked with drifting ice, and months-long darkness keep most ships away from the high Arctic.

Yet three summers ago a research crew braved those conditions to hunt for something utterly invisible from the surface: cracks in the seabed that gush scalding fluid.

Their gamble paid off with the discovery of Jøtul, the first hydrothermal vent field ever seen along a 311-mile stretch of the Knipovich Ridge between Greenland and Svalbard.

Hydrothermal vents have fascinated scientists since the first ones were spotted in 1977 near the Galápagos. Each site shows how seawater plunges through fractured crust, meets magma, then returns loaded with metals and other chemicals at temperatures hot enough to melt lead.

What Jøtul adds to the story is location. It sits almost 1.9 miles below sea level on one of Earth’s slowest-spreading ridges – plates here drift apart at less than 0.8 inches per year.

What’s surprising is that these vents aren’t located in the usual place (on the central ridge where magma rises to the crust), but off to the side, likely because of the unique way this part of the Earth is breaking apart. The find hints that many Arctic vents are still waiting in the dark.

Hydrothermal vents under the ice

Most mid-ocean ridges lie in temperate or tropical seas, so the Arctic version has remained poorly mapped. Satellite altimetry reveals the ridge arcing 2,485 miles across the ocean floor, but the thickness of pack ice limits sonar surveys and dive time for crewed vessels.

Robots changed the game. In 2021, a drone-like autonomous vehicle detected odd chemical spikes in water samples scooped 1,000 feet above the seabed.

Sensors showed plumes from hydrothermal vents rich in hydrogen and manganese – classic vent fingerprints.

The team returned with the remotely operated vehicle MARUM-QUEST and guided it down through blackness to the source.

Cameras soon showed spires of shimmering water raining metal flakes. Vent fluid, hotter than 600.8 °F, bursts from narrow chimneys nicknamed black smokers.

Nearby, cooler, clear jets issued from cracked pillow basalt. Their offset position, roughly half a mile east of the ridge axis, supports the idea that magma here travels sideways through faults before heating trapped seawater.

Slow motion hydrothermal vents

Circulation in hydrothermal vents thrives where fresh crust forms quickly, so slow ridges such as Knipovich were once thought nearly barren. That assumption is fading.

Other Arctic sites, including Aurora and Loki’s Castle, have already proved active despite meager magma supply. Jøtul strengthens the pattern and suggests that slowness breeds variety.

Some ‘black smoke’ chimneys stood tall and sulfur-coated; others lay toppled and dark, evidence of past pulses.

“Water penetrates into the ocean floor where it is heated by magma. The overheated water then rises back to the seafloor through cracks and fissures.

“On its way up, the fluid becomes enriched in minerals and materials dissolved from the oceanic crustal rocks,” explains Prof. Gerhard Bohrmann of MARUM and chief scientist of the MARIA S. MERIAN (MSM 109) expedition.

“These fluids often seep out again at the sea floor through tube-like chimneys called black smokers, where metal-rich minerals precipitate,”

Why methane matters

Hydrothermal vent fields normally pump out hydrogen sulfide and iron, but Jøtul adds another twist: exceptionally high methane.

“The Jøtul Field is a discovery of scientific interest not only because of its location in the ocean but also due to its climate significance, which was revealed by our detection of very high concentrations of methane in the fluid samples, among other things,” Bohrmann noted.

Methane bubbles rising from a depth of three miles rarely reach the air intact; bacteria and oxidation convert much of the gas into carbon dioxide before it surfaces. Even so, deep plumes eventually feed the global carbon cycle.

Geologists suspect that thick sediment piles once buried above the ridge now melt and release hydrocarbons when magma intrudes, a recipe unique to slow, sediment-rich Arctic basins.

Tracking how much methane escapes will sharpen climate models that already struggle with seafloor emissions.

Life without sunlight

No sunlight penetrates the water column that far north and that deep, yet the Hydrothermal vent chimneys crawled with limpets and white polychaete worms.

Bacterial mats coated nearby rocks like wet paper. Instead of photosynthesis, these organisms run on chemosynthesis: microbes oxidize hydrogen sulfide or methane, and larger animals harvest the microbial energy through grazing, filter feeding, or symbiosis.

Similar communities have inspired theories that life’s earliest ancestors could have evolved in vent habitats four billion years ago.

Arctic vents challenge that narrative because their chemistry and mineralogy differ from tropical counterparts.

Cooler seeps here permit carbonate as well as sulfide deposits, and the extreme seasonal swing in surface productivity may shower additional organic matter on resident fauna.

Biologists plan to compare DNA from Jøtul’s inhabitants with samples from vents farther south to see whether polar isolation has driven new species to emerge.

What happens next?

Later this summer the MARIA S. MERIAN will head back to the ridge with upgraded sensors and a drill capable of coring living chimneys.

Researchers want time-series data on plume height, fluid composition, and vent temperature. They will also map the seafloor around Jøtul in finer detail, looking for smaller seeps missed on the first pass.

Results will feed the Bremen-based project “The Ocean Floor – Earth’s Uncharted Interface,” which links geology, biology, and climate science.

Each new hydrothermal vent field discovered shifts attention toward the vast unexplored sections of the global ridge system. Only about one-fifth of Earth’s seafloor has been mapped at the resolutions necessary to spot vent chimneys.

As autonomous vehicles grow tougher and satellite communications improve, the Arctic – once an afterthought – may become the next frontier for studying how oceans, rocks, and atmosphere work together. Jøtul is a reminder that even in 2025 our planet still keeps fiery secrets under the ice.

The full study was published in the journal Scientific Reports.

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