Deep within Earth’s mantle lie two enormous regions, often referred to as "islands," which are the size of continents.

Far below the familiar blue of the oceans, scientists are uncovering evidence of a vast hidden reservoir of water locked inside the rocks of Earth’s mantle. Rather than a single underground sea, this ...

Earth’s early history is undergoing a quiet revolution. Long assumed to be dry at its core, new research suggests our planet may have formed with a massive internal water reservoir—locked deep within ...

Add Yahoo as a preferred source to see more of our stories on Google. The slice you see cut out of the Earth reveals its core, depicted here in bright yellow. fhm/E+ via Getty Images Our Earth is ...