A stunning new study published in Nature has revealed what scientists are calling a “hidden ocean” buried 400 miles below ground.
It is locked inside a mineral you’ve probably never heard of: ringwoodite.
So how does this work?
Turns out, ringwoodite—found deep in Earth’s mantle—can trap water inside its crystal structure under massive pressure.
“It’s like a sponge for hydrogen,” said geophysicist Steve Jacobsen.
“We’ve been hunting for this deep water for decades.”
And we’re not talking puddles—this underground stash might rival the total volume of all surface oceans.
Why Does It Matter?
This could change everything we know about Earth’s water cycle.
The discovery suggests there’s a whole-Earth water loop happening far beneath us.
It is tied to volcanic eruptions, earthquakes, and the movement of tectonic plates.
Seismologist Brandon Schmandt added, “We found melting at depths no one expected.
That’s a smoking gun—water is down there, and it’s active.”
Bottom line? Earth isn’t just a blue planet because of its oceans.
It might be soaking wet from the inside out.
