The transition zone sits between the Earth’s upper and lower mantle layers, some 250 to 400 miles beneath the Earth’s surface.
Hoping to learn more about the significance of water-holding ringwoodite and plate tectonics, researchers studied seismic movement throughout the mantles. They discovered that as mantle material flows downward, it melts while crossing from the transition zone into the lower mantle: proof that there must be water present, as melting is a water expulsion method.
According to Brandon Schmandt, a seismologist at the University of New Mexico, “If we are seeing this melting, then there has to be this water in the transition zone. The transition zone can hold a lot of water, and could potentially have the same amount of H2O as all the world’s oceans.”
So, does the Earth’s mantle hold as much if not more water than all the Earth’s oceans combined?
First, scientists will have to discover if this reservoir wraps all the way around the planet. Between the seismology study, which showed that seismic waves from over 500 earthquakes slow down as they move downward, indicating the presence of damp rocks under the United States, and the diamond with ringwoodite that confirmed the mineral can hold water, the evidence is looking pretty good.
Certainly it’s not an ocean as you or I know it, but the presence of a massive reservoir of water could be one of the biggest discoveries ever made.
This would teach us all more about the origin of water on the planet, as well as the natural water cycle (the underground reservoir in its place keeps the entire planet from flooding), and how tectonic plates move. Sometimes, even the biggest discoveries can be found in the tiniest of minerals.
SHARE this with your science-loving friends!