Geologists at Northwestern University have made a stunning discovery that may help explain the origins of our oceans.

TIME reports Steve Jacobsen and a team of geologists made the discovery. In order to figure out what was underneath the surface of the water, they used seismometers, which allowed them to study seismic wave speed as the result of earthquakes.

When the waves reached ringwoodite, which is a blue rock layer, they would become slower. This indicated to them that the waves passed through both water and rock.

According to the Huffington Post, the findings indicate that ringwoodite could hold three times the amount of water that exists in the oceans of our planet. The discovery could also explain plate tectonics when water has an affect on a rock when it shifts in the Earth’s outer crust.

In a statement by the geophysicist, Jacobsen said, “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.”

He also reportedly told NewScientist “It’s good evidence the Earth’s water came from within.”

A laboratory experiment was done to replicate the ringwoodite that was found in the discovery. Scientists were able to determine that by attracting hydrogen, ringwoodite could absorb water, as reported by The Guardian.

Reportedly, more experiments would be needed in order to find out where ringwoodite could be found on other parts of the planet. As of now, he has only found that this rock is beneath the United States.