A team of scientists has detected the presence of a huge reservoir of water, three times larger than all the oceans, located 700km deep below the surface of the Earth.
What if the origin of water on Earth came from there, from its mantle? This is the question posed by a team of researchers behind an incredible discovery. Indeed, they discovered the presence of a gigantic ocean located more than 700km deep, under the surface of the Earth. So gigantic that its extent is three times greater than all the oceans present on the surface.
This mysterious water reservoir is hidden in the heart of a blue rock, known as ringwoodite, 700km deep in the Earth’s mantle, that is to say the layer of hot rocks located between the surface of the Earth and its core.
Its immense size could help explain the origin of water on Earth according to scientists. This discovery effectively lends credence to a theory that the oceans gradually seeped out from inside the Earth. On the other hand, the theory putting forward the impact of comets takes the lead in the wing.
«This is tangible proof that the water on Earth came from within,» said Steven Jacobsen, a researcher at Northwestern University in Illinois, and lead author of the study.
According to him, this hidden water could also serve to maintain the size of the oceans which never has for millions of years.
To reach this discovery, the team of researchers used no less than 2,000 seismographs across the United States to study the seismic waves generated by more than 500 earthquakes. Traveling inside the Earth , including the core, these seismic waves can be detected on the surface.
By measuring the speed of these waves, as a function of depth, the researchers were able to determine what type of rocks they were passing through. This is how they detected this huge reservoir of water because the waves slowed down as they passed through the wet rock: “It is a layer of rocks with water along the ridges between the grains, a bit as if they were sweating” .
“We should welcome the presence of this reservoir. If it weren’t there, it would be on the surface of the Earth and the mountain tops would be the only visible land,” says Steven Jacobsen.
Now, researchers hope to collect more seismic data across the planet to determine whether mantle melting is common or not. Their results may help to understand the water cycle on Earth.