A stunning new place has been discovered, hidden deep beneath the ocean waves of the Arctic Circle.
Off the coast of Svalbard, Norway, more than 3,000 meters (9,842 feet) below, a field of hydrothermal vents unfolds along Knipovich Ridge, an underwater mountain range previously thought to be quite inconspicuous.
Instead, like underfloor heating, volcanic activity beneath the seafloor causes heat to seep in, creating a haven of warmth and chemical reactions where life can gather and thrive.
The field, measuring at least a kilometer in length and 200 meters in width, is named Jøtul, after the giants of Norse mythology who live under the mountains. In this case, the giant is the internal processes of the Earth, released through cracks in the sea floor.
“Water penetrates the ocean floor where it is heated by magma. The superheated water then rises back to the sea floor through cracks and fissures,” explains marine geologist Gerhard Bohrmann of the University of Bremen in Germany.
“On its way up, the fluid is enriched with minerals and dissolved materials from the rocks of the oceanic crust. These fluids often seep back to the seafloor through tube-like vents called black smokers, where the metal-rich minerals are then precipitated .”
Hydrothermal vents are some of the most interesting underwater environments. They are usually very deep below the surface of the ocean, so far that light from the Sun cannot penetrate the vast volume of water above them.
At these depths, conditions are permanently dark, bitterly cold and surrounded by crushing pressures.
This environment isn’t exactly conducive to life, but hydrothermal vents act as strange oases. Minerals that flow and dissolve in water provide the basis for a food web dependent, not on photosynthesis like most life closer to the surface, but on chemosynthesis—using chemical reactions for energy, rather than sunlight.
These environments create a deep seabed far more dynamic and thriving than might be expected, giving us a clue as to how life might appear on worlds very different from our own.
Finding hydrothermal vents is also important to the effort to protect Earth’s biodiversity and learn more about how it works, as well as understanding how the planet itself works and changes over time.
The Jøtul field is located right at the boundary between two of Earth’s tectonic plates, at what is known as a slow-spreading ridge. The plates are moving away from each other very slowly, which causes the crust to stretch and develop valleys and ridges.
Scientists have detected hydrothermal activity along almost all ridges in northern Iceland, but the Knipovich Ridge remained a notable exception.
That was, until 2022. Scientists had seen hints of hydrothermal chemistry in the region, so they took a remotely piloted submersible to the ridge to see if they could find its source.
They drove MARUM-QUEST diver more than 3 kilometers to the bottom of the sea, where he took images and took samples from the waters. And there, they found the Jøtul Field—a vast region of seafloor with extinct and active hydrothermal vents, and a telltale glow of volcanic heat seeping into the water.
It’s a remarkable discovery, one that fills an important and previously unknown gap in the hydrothermal profile of the Norwegian-Greenland Sea.
“The Jøtul hydrothermal field is the first to be discovered along the 500 kilometer long ultra-slow spreading Knipovich Ridge and is significant because it represents a new link between the active Loki Castle hydrothermal systems at the bend of Mohns and Knipovich Ridges and the field hydrothermal Aurora of the Gakkel Ridge”, the researchers write in their paper.
“Since these systems are separated by a distance of more than 1,000 kilometers, the discovery of the Jøtul hydrothermal field is important for understanding the distribution of the chemosynthetic faunal community.”
In addition, the new discovery could help provide insights into ocean chemistry and how the waters that coat our world help circulate and distribute materials such as carbon.
The research was published in Scientific Reports.