Researchers at Northwestern University have found evidence for a massive reservoir of water deep within the Earth's mantle. The reservoir, which is said to be three times the volume of the oceans on the surface, is contained within highly-pressurized rock known as ringwoodite. The scientists hope that their findings, recently published in the journal Science, can shed light on where Earth's oceans came from. THREE TIMES THE VOLUME OF THE OCEANS ON EARTH'S SURFACE The team, led by mineralogist Steven Jacobsen, used an array of 2000 seismometers to study how seismic waves generated by earthquakes move through the Earth's interior....