Water, the element that makes Earth our “blue planet,” continues to raise questions about its origins. How did it get here? The most common theories suggested that it was brought by icy asteroids or comets. But a groundbreaking study from 2014, published in the journal Scienceopened new horizons. Scientists have discovered a huge reservoir of water trapped deep in the Earth’s mantlea reserve so vast that it exceeds three times the volume of all the oceans combined.
The discovery of this “hidden ocean” around 700 kilometers deep has shocked scholars. It is found in the Earth’s mantle, an area believed to be made up exclusively of incandescent rocks and magma. Here, water is trapped in a rare and mysterious rock: the ringwooditea deep blue mineral similar to peridot, often used in jewelry. “Ringwoodite is like a sponge that absorbs water”explained Steven Jacobsen of Northwestern University. “Thanks to its special crystalline structure, it can attract hydrogen and retain large quantities of water under conditions of extreme pressure and temperature.”
The discovery was made using a network of 2,000 seismometersinstruments that analyzed seismic waves generated by over 500 earthquakes. These movements of the earth’s crust allow us to “look” into the heart of the planet. The waves, slowed by wet rocks, provided the key evidence. “At those depths, the water is not liquid, but bound to the rocks, as if they were sweating”added Jacobsen.
Water on Earth could come from inside
This finding supports an extraordinary hypothesis: water on Earth may come from its depths and not from space. The study suggests that water trapped in the mantle may have risen to the surface over millions of years, contributing to the formation of oceans, seas and rivers.
“If it weren’t for this hidden reservoir, the Earth’s surface would be almost completely submerged in water”Jacobsen said. This confirms the existence of a global water cycle, which connects the Earth’s mantle with the surface oceans, profoundly changing our understanding of the Earth.
The discovery of ringwoodite and the hidden water reservoir opens up new questions about planet formation. What is the role of these “internal oceans” in the earth’s balance? And how do they affect our climate and geological activities? “Earthquakes and volcanoes are just a small expression of what happens in the heart of the Earth”concluded Jacobsen. This research could help us better understand not only our planet’s past, but also its future.
