Hidden ocean discovered deep underground near Earth's core
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We may have another "ocean" to add to the world map -- only this one is hidden beneath our planet's surface.
A study suggests that a hidden "ocean" is nestled in the Earth's mantle 400 miles beneath North America.
The massive hidden reservoir, apparently locked in a blue crystalline mineral called ringwoodite may
hold three times as much water that exists in all the world's surface oceans.
This discovery may help explain where Earth's water supply came from, and how subterranean water
affects the shifting of rock in the Earth's outer crust -- a phenomenon scientists call plate tectonics.
"Geological processes on the Earth’s surface, such as earthquakes or erupting volcanoes, are an expression of what is going on inside the Earth, out of our sight," geophysicist Dr. Steven Jacobsen said in a written statement. "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 deep water for decades."
We may never know 
