Massive Deep-Earth Reservoir Holds Triple the Volume of Surface Oceans
Researchers in the Earth sciences have uncovered evidence of a massive water reservoir located 660 kilometers beneath the planet’s surface, a finding that suggests the Earth’s interior houses a volume of water capable of tripling known surface oceans. Published in the journal Science, the study changes previous models of how water is distributed and stored within the planet. As NSC Total reported, scientists analyzed data combining high-pressure laboratory experiments with seismic readings from the USArray network in North America to map the hidden liquid volume.
Ringwoodita Acts as a Subterranean Sponge for Deep Water
The water does not exist as an underground sea with open waves or currents. Instead, it is trapped inside a blueish rock known as ringwoodita, which sits within the mantle’s transition zone between 410 and 660 kilometers deep. This mineral features a unique crystal structure that acts as a natural sponge, attracting hydrogen and locking the element inside its lattice under extreme pressure. According to calculations by Northwestern University geophysicist Steve Jacobsen, if just one percent of the rock mass in the transition zone contained this hydrated mineral, it would equal nearly three times the water volume of all surface oceans combined.
Brazilian Diamond Confirms Deep Mantle Hydration
Physical evidence of this hidden reservoir first gained major traction in 2014, when researchers examined a diamond extracted from Juína, Mato Grosso, Brazil. The sample contained a tiny inclusion of ringwoodita with about 1.5 percent water by weight, as detailed by the University of Alberta and published in the journal Nature. While earlier theories relied entirely on theoretical models and laboratory simulations, the Brazilian diamond provided direct physical proof that hydrated minerals exist deep beneath the crust. Seismologists using the USArray network later identified signals of partial rock melting near the lower boundary of the transition zone, suggesting that downward-moving tectonic plates transport water into the mantle while ascending geological processes release it.
Global Hydrologic Cycle Links Interior Mantle to Surface Seas
This deep circulation system redefines the Earth’s water cycle, pointing to an internal origin for surface moisture rather than a bombardment of icy comets during the planet’s early formation. Steve Jacobsen noted to New Scientist that the hidden reservoir acts as a continuous underground basin, stabilizing sea levels over millions of years by exchanging water between the surface biosphere and the deep interior. Without this massive mantle sponge pulling moisture downward, geological models indicate that water would cover the entire globe, leaving only mountain peaks exposed above the surface.
Frequently Asked Questions About the Deep-Earth Reservoir
Is there an open ocean of liquid water beneath the crust?
No, the water is not liquid. It is chemically bound inside the crystal structure of high-pressure minerals like ringwoodita, meaning it exists as a hydrated rock rather than a subterranean sea with tides or currents.
How deep is the transition zone where the water is stored?
The transition zone sits between 410 and 660 kilometers below the Earth’s surface, where intense pressure and temperature force minerals to adopt structures capable of trapping hydrogen and oxygen.
How much water does the deep mantle hold compared to surface oceans?
Calculations by Northwestern University researchers indicate that the transition zone could hold between three and six times the volume of all surface oceans combined, depending on how much of the rock is actually hydrated.
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