Recent research has confirmed the existence of a massive water reservoir located approximately 700 kilometers beneath Earth’s surface. This hidden ocean is locked within a mineral called ringwoodite, which acts like a natural sponge, trapping water within its crystalline structure. The discovery challenges our understanding of Earth’s water cycle and could even provide clues in the search for extraterrestrial life.
Ringwoodite: The Mineral That Holds Oceans
Ringwoodite, first discovered in Earth’s rock formations in 2008, contains up to 1.5% water by weight. Scientists from Northwestern University and the University of New Mexico found that this mineral stores vast amounts of water within the transition zone between Earth's upper and lower mantle.
Seismic data revealed a process called “dehydration melting”—as ringwoodite descends deeper, it releases trapped water, contributing to partial melting of the surrounding rock. This explains the presence of magma within Earth's mantle and suggests a vast, hidden network of underground water reservoirs.
Where Did Earth's Water Come From?
Before this discovery, scientists debated whether Earth's oceans originated from cometary impacts or were present within the planet since its formation. This new evidence supports the theory that water has always been a fundamental part of Earth's interior and gradually emerged over millions of years.
This hidden water reservoir may also act as a “buffer”, maintaining a stable volume of Earth's surface oceans over geological timescales. If all of this underground water were suddenly released, large portions of the planet’s landmass could be submerged.
Implications for Science and the Search for Life
The discovery also has implications for astrobiology. If similar water-containing minerals exist on other planets, it could mean that liquid water is trapped beneath their surfaces, increasing the possibility of extraterrestrial life.
Scientists are now conducting further studies on ringwoodite, using advanced X-ray spectroscopy and laser heating technology to understand its properties. These experiments will provide deeper insights into Earth's formation, its internal processes, and the role of water in planetary evolution.
The discovery of ringwoodite is just the beginning of a new era in Earth sciences, redefining our knowledge of geology, climate, and the history of our planet.