Mantle's Hidden Ocean Could Rewrite Earth's Water Story
Scientists report a vast water reservoir stored in the mineral ringwoodite about 700 kilometers beneath Earth's surface, forming a deep 'ocean' three times larger than all surface oceans. The finding, supported by seismic data from thousands of sensors and high-pressure lab experiments, challenges the idea that Earth's water came mainly from comets and suggests interior sources could help regulate surface oceans and geologic activity.