Is There an Ocean Beneath the Earth’s Crust?

image courtesy of

image courtesy of

Have you ever fantasized about a Middle Earth-like world beneath the Earth’s crust, or deep in the ocean, where only mythical creatures can live? What if such a place really exists?

The discovery of a seemingly worthless brown diamond in a riverbed in Mato Grosso, Brazil, has made those fantasy worlds of our childhood a little more believable.

University of Alberta diamond expert Graham Pearson came across a 3 millimeter (0.118 inches) diamond that contained a small sample of a mineral that has never been found to naturally occur outside of the Earth’s mantle: Ringwoodite. Through analysis, it was found that 1.5 percent of this mineral’s weight was from water that had been trapped within the mineral as it formed. According to Professor Pearson, “This sample really provides extremely strong confirmation that there are local wet spots deep in the Earth in this area. That particular zone in the Earth, the transition zone, might have as much water as all the world’s oceans put together.”

Hans Keppler of the University of Bayreuth in Germany analyzed Pearson’s findings and determined that they “confirm predictions from high-pressure laboratory experiments that a water reservoir comparable in size to all of the oceans combined is hidden deep in the Earth’s mantle.”

Scientists have thought for a long time that there are reservoirs of water hidden beneath the Earth’s crust, but have had no proof. With the discovery of this mineral, scientists can pinpoint the location of these oceans to the transition zone, located between the Upper Mantle and the Lower Mantle, approximately 410-660 km (255-410 miles) beneath the Earth’s surface.

Pearson offers two possible reasons why the Ringwoodite would contain that much water: Either the chemical makeup and the extreme pressure the mineral is formed under spontaneously create water, or the water and Ringwoodite are already there before the diamond formed over both. Either explanation implies that the transition zone does contain water, even if it is only localized.


-Morgan Forester & Nick LeBlanc