Researchers from Northwestern Univ. and the Univ. of New Mexico report evidence for potentially oceans worth of water deep beneath the U.S. Though not in the familiar liquid form—the ingredients for water are bound up in rock deep in the Earth’s mantle—the discovery may represent the planet’s largest water reservoir.
The presence of liquid water on the surface is what makes our “blue planet” habitable, and scientists have long been trying to figure out just how much water may be cycling between Earth’s surface and interior reservoirs through plate tectonics.