China’s CAS Finds Largest Known Hydrogen Vent System Undersea

During a deep-sea exploration of the Pacific Ocean, a piloted submersible has discovered a massive underwater “metropolis” — a vast system of deep craters and dolomite walls that completely eclipses the famous “Lost City” in the Atlantic, CE Report quotes Kosova Press.

Through a curtain of constantly falling marine “snow,” the strange carbon walls and jagged rocks glow with heat, creating a mirage-like scene in the deep sea.

Covering an area of 11.1 square kilometers, the newly discovered hydrothermal field is over 100 times larger than its Atlantic counterpart.

The “Lost City”, with its distinctive towers and domes, was discovered in 2000 near the Mid-Atlantic Ridge and has long been considered the largest known hydrothermal vent field in the world.

Researchers from the Laoshan Laboratory and the Chinese Academy of Sciences (CAS) have named the Pacific site the Kunlun Hydrothermal Field.

Like the Lost City, Kunlun is rare and may offer even deeper insights into how life on Earth began. It emits hydrogen-rich fluids at temperatures below 40°C — significantly cooler than the typical “black smoker” vents, which resemble underwater chimneys.

The hydrogen-rich fluids at Kunlun are believed to resemble the “hot soups” that may have existed on Earth billions of years ago when life first emerged.

“What’s especially interesting is the ecological potential,” said marine geochemist Weidong Sun of CAS.

“We observed a diverse range of marine life thriving in this environment — including shrimp, squat lobsters, anemones, and tube worms — species that may rely on hydrogen-powered chemosynthesis.”

Researchers estimate that Kunlun contributes up to 8% of the world’s abiotic hydrogen flux from all oceanic sources — a massive contribution from a single site.

Unlike the Lost City, which features sharp, spire-like dolomite peaks, Kunlun's craters can span hundreds of meters in diameter and descend more than 100 meters deep.

So far, most known hydrogen-rich vent fields have been found near spreading tectonic plates. However, Kunlun lies 80 km west of the trench, within the Caroline Plate, a location that challenges previous geological assumptions.

Researchers also note that this deep-sea ecosystem, rich in life, could become an ideal target for hydrogen exploitation as a future energy source.

“The Kunlun system is unique not only because of its extraordinarily high hydrogen flux but also its size and geological setting,” said Sun.

“This shows that hydrogen production driven by serpentinization can occur far from mid-ocean ridges, challenging prior assumptions.”