Scientists scanning the deep interior of Earth have found evidence of a vast water reservoir beneath eastern Asia that is at least the volume of the Arctic Ocean. The discovery marks the first time such a large body of water has found in the planet’s deep mantle. The finding, made by Michael Wysession, a seismologist at Washington State University in St. Louis, and his former graduate student Jesse Lawrence, now at the University of California, San Diego, will be detailed in a forthcoming monograph to be published by the American Geophysical Union.
This is an incredible find, and maybe even more incredible that it’s only being discovered now. It’s not looking as though the water could be "captured" for future use, as most activity that deep causes evaporation.
Source: Live Science