Scientists probing hidden ‘ocean’ under the Earth’s crust…and it’s as big as all the seas on the surface combined
BENEATH the Earth’s crust is an ‘ocean’ that contains almost as much water as the Pacific, Atlantic and Indian oceans combined, scientists have discovered.
That’s the result of a study on the mantle – the layer of the planet between the crust and the core.
“The total amount of water in the deep Earth is nearly the same as the mass of all the world’s ocean water,” professor Hogzhan Fei at the University of Bayreuth in Germany told New Scientist.
It is well-accepted in the scientific community that the upper and lower mantles are dry.
But whether the transition zone between them is dry remained a topic of dispute.
Fei and his colleagues doused water on rocks that are typical to the mantle transition zone – a buffer 255-410 miles beneath us that separates the upper and lower mantles.
What they found is that the viscosity levels of wet rocks match the measured levels of the mantle.
Fei said: “We therefore conclude that the mantle transition zone should be wet.”
It is also possible that the Earth is “wet all the way down to its core”.
Another experiment reveals that the Earth makes its own water from scratch from the mantle.
Earth’s huge water storage could come from chemical reactions in the mantle instead of collisions with ice-rich comets during primeval times.
The water underneath does not slosh around but instead is kept in storage.
Broken into its composite hydrogen and oxygen atoms, the water is locked up within the crystals of its surrounding minerals.
As the water finally escapes the crystals, it may be under such pressure that it can trigger earthquakes hundreds of miles below Earth’s surface – tremors whose origins have so far remained unexplained.
Professor John Tse at the University of Saskatchewan in Canada told New Scientist: “Water formed in the mantle can reach the surface via multiple ways, for example, carried by magma in the form of volcanic activities.”
It is possible that water is still being made this way deep inside Earth today, and the same could be true of other planets.
It is still unknown how much of the Earth’s water arrived from beneath the crust/
The scientific community continues to debate the potential origins of water on our planet.
Steven Jacobsen of the Northwestern University of Illinois shared with New Scientist: “It’s a key question about the evolution of the Earth, which extends to extrasolar planets as well.”
Previously, scientists detected a mysterious element in ancient lava – leading to theories that the Earth’s core is leaking.