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. Looking down deep The pair analyzed more than...