Scientists have recently discovered a vast ocean concealed beneath the Earth’s crust as an immense reservoir of water, stored in rock known as “ringwoodite”, 400 miles below the surface.

Researchers found water stored inside mantle rock in an unconventional sponge-like state — neither solids, liquid, nor gas, but a novel fourth state, Indy100 reported.

The findings were published in a 2014 scientific paper, titled “Dehydration melting at the top of the lower mantle”.

“The ringwoodite is like a sponge, soaking up water, there is something very special about the crystal structure of ringwoodite that allows it to attract hydrogen and trap water,” said geophysicist Steve Jacobsen, who was part of the team behind the discovery at the time.

“This mineral can contain a lot of water under conditions of the deep mantle.”

He added: “I think we are finally seeing evidence for a whole-Earth water cycle, which may help explain the vast amount of liquid water on the surface of our habitable planet. Scientists have been looking for this missing deep water for decades.”

These findings were made after scientists were studying earthquakes and discovered that seismometers were picking up shockwaves under the surface of the Earth.

As a result, they were able to establish that the water was being held in the ringwoodite.

According to the scientists, if the rock contained just 1% water, it would mean that there is three times more water beneath the Earth’s surface than in its oceans on the surface.

Additionally, in another significant discovery made by scientists earlier, they found a new ecosystem when turning over volcanic crust with an underwater robot.