Independent/- Scientists recently discovered that water slowly seeps from the Earth’s surface to the inner core. The liquid falls below the descending tectonic plates, before eventually reaching the core after a 2,900-kilometre journey.
Although the process is slow, over billions of years it has formed a new surface between the molten metal in the outer core and the Earth’s outer mantle.
In a new study, scientists at Arizona State University said that the water triggers a chemical reaction, leading to the formation of a new layer that is “a few hundred kilometers” thick. (That’s “thin” when it comes to the Earth’s inner layers.)
Co-author Dr Dan Shim wrote: “For many years, the physical exchange between the Earth’s core and mantle was thought to be small. However, our recent experiments at high pressure reveal a different story.”
“We found that when water reaches the core-mantle boundary, it reacts with the silicon in the core, forming silica.”
“This discovery, combined with our previous observation of diamonds forming from the reaction of water with carbon in liquid iron under extreme pressure, indicates a much more dynamic interaction between the core and mantle, indicating a significant physical exchange.”
The Arizona State University statement said: “This discovery enhances our understanding of the Earth’s internal processes, indicating a global water cycle that is more extensive than previously recognized.”
“The changing ‘film’ of the core has profound implications for the geochemical cycles linking the surface water cycle to the deep mineral core.”
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