Imagine an ocean three times the size of all surface oceans combined, hidden hundreds of kilometers beneath our feet. That's the implication of a recent geological discovery in France, potentially revolutionizing our understanding of Earth's water cycle.
This subterranean ocean, located approximately 640 kilometers below the surface, isn't a free-flowing body of water. Instead, the water is trapped within a mineral called ringwoodite, whose unique crystal structure acts like a sponge.
Geophysicist Steve Jacobsen describes ringwoodite as a mineral that absorbs and retains water within its matrix. Analysis of seismic waves, generated by earthquakes, revealed unexpected behavior as they passed through the Earth's mantle, indicating the presence of water-laden rock.
This discovery challenges previous assumptions about Earth's interior, suggesting a far wetter mantle than previously thought. The ringwoodite's capacity to trap water implies a global water cycle extending deep into the mantle, potentially influencing volcanic activity and tectonic processes.
The implications extend beyond Earth, prompting reconsideration of planetary habitability. Similar water storage processes could occur on other rocky planets, potentially supporting water's existence in unexpected places.