Scientists believe they’ve found evidence of a potential ocean beneath our home planet’s crust. A study from researchers at Northwestern University and the University of New Mexico have concluded the body of water rests about 400 miles underneath earth’s crust and is so large it can fill all our oceans three times over.

Scientists believe they’ve found evidence of a potential ocean beneath our home planet’s crust. A study from researchers at Northwestern University and the University of New Mexico have concluded the body of water rests about 400 miles underneath earth’s crust and is so large it can fill all our oceans three times over.

Their research however indicates the water is not in the typical liquid, ice or vapor forms, but instead, is trapped in mantle rock containing a blue mineral called ringwoodite. Ringwoodite has a structure similar to crystal that acts like a sponge to trap liquid and pull in hydrogen. Thus far only one small piece of ringwoodite has been brought to Earth’s surface from 400 miles underground by volcanic activity and was found to contain water in solid form. The researchers combined lab experiments on mantle rock under high pressure with seismic data measuring U.S. earthquakes to reach their conclusions.

The discovery is an important one as it will help scientists learn how the Earth formed and its current composition. Northwestern geophysicist Steve Jacobsen, who is a co-author of the study, commented “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.”