London. Till now we have believed that the Earth’s water is limited to its surface. But new research has made an important revelation. There is a huge ocean hidden within the mantle 700 kilometers below the Earth’s surface. The discovery, led by a team at Northwestern University, raises questions about the planet’s water cycle, and challenges long-held beliefs about the origin of Earth’s water.
Ringwoodite: The key to Earth’s mantle water
Scientists estimate that this underground reservoir could be three times larger than the total area of all the oceans combined. However, unlike the surface oceans, this “hidden ocean” is not made of liquid water. Instead, the water is locked within the crystal structure of a rare blue rock called ringwoodite, which is found deep within the mantle.
The research team, led by Steven Jacobson, used more than 2,000 seismographs deployed across the United States to track seismic waves from more than 500 earthquakes. These seismic waves slow down significantly at certain depths, indicating the presence of water-rich rocks. By measuring the speed of these waves at different depths, scientists can infer the existence of water trapped inside the mantle.
Implications for Earth’s water cycle and origins
This seismic discovery suggests that the origins of Earth’s water cycle may lie much deeper than previously thought. Traditionally, it was believed that water came from comets hitting Earth. Now, scientists are considering that water may seep up from the Earth’s interior over millions of years.
The implications of this discovery are far-reaching. This underground ocean may play an important role in regulating the long-term stability of Earth’s surface water, potentially cycling water between the planet’s surface and its interior. Further studies are now being planned to find out whether similar water reserves exist elsewhere in the world, which could lead to new changes in our understanding of water distribution on the planet.