Scientists propose new theories on Earth's water origins and deep reservoirs

Researchers have provided new insights into the presence and origins of water on Earth. Evidence suggests a massive reservoir of water exists within the Earth's mantle, specifically in the transition zone located between 410 and 660 kilometers below the surface. This water is not in a liquid form but is trapped within the crystalline structure of minerals like ringwoodite, a high-pressure form of olivine. A diamond found in Mato Grosso, Brazil, containing ringwoodite with approximately 1.5% water by weight, has served as direct evidence for this hydrated layer.

In a separate study published in Nature Geoscience, scientists from the University of Mexico and the University of New Mexico propose that Earth's water may have been produced locally rather than arriving via external sources like comets. The theory suggests that iron-oxide-rich rocks falling through the young planet's extreme heat and hydrogen-rich atmosphere reacted to create water and pure iron. This process would have contributed to the formation of the planet's metallic core approximately 4.5 billion years ago.