Scientists discover massive 'ocean' beneath Earth's surface bigger than all the seas above land

Scientists have discovered a huge pool of water beneath the Earth's surface.

The huge supply of water is actually hidden underneath the Earth's crust, and it's three times bigger than the oceans that sit on the surface.

Mind-boggling, right?

It was discovered pretty recently, too - with scientists finding it all the way back in 2014.

Considering it's hidden a whopping 400 miles underground, it's not exactly accessible.

It's contained inside a blue rock known as 'ringwoodite' in the Earth's mantel, which acts as a sort of sponge for that huge body of H2O.

So it's not a liquid, solid, or gas, but a fourth molecular structure of water contained inside the mantle rock.

READ MORE:

THIS IS WHY THE EARTH COULD LOSE A SECOND IN THE FUTURE

SCIENTISTS DISCOVER MASSIVE SOLID BALL INSIDE EARTH'S CORE

"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 monumental discovery.

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

Getty Stock Photo

The watery rock was discovered by scientists from Northwestern University in Illinois using seismometers to measure the waves being generated by earthquakes across the US.

In their research, they found that the waves weren't limited to the Earth's surface, but moving throughout the planet's core.

By measuring the speed and depth of those waves, researchers were able to work out what sort of rocks the water was being contained in - landing on ringwoodite in the end.

The substance can contain up to 1.5 percent water, and if the ringwoodite under the surface has just 1 percent water in its molecular build-up, it would mean that it holds three times more water than all of the oceans on the Earth's surface.

So why is it important?

Bettmann/Getty Stock Images

Well, the discovery could help scientists determine how Earth was formed, furthering the theory that the Earth's water 'came from within', rather than from asteroids and comets.

Jacobsen explained at the time: "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."

Moving forward, Jacobsen and his team want to determine whether or not this layer wraps around the entire planet Earth.