The journal Nature announced a diamond discovery that helped settle a dispute about the Earth’s composition. The dispute concerned whether there is water in the transition zone — the portion of the Earth’s mantle 250 to 410 miles underground. Skeptics have argued that water cannot exist at that depth...At around 310 miles underground, wadsleyite is pressed into ringwoodite. Both substances can hold water. Now, geophysicists working in Brazil have uncovered a diamond containing ringwoodite that came steaming out of a volcano...The paper emphasized the volume of water likely to be present in the transition zone — possibly more than all of the oceans combined. But it’s at least 250 miles underground, and we’ve never drilled deeper than seven.
The subject is covered in greater detail at Scientific American, where they indicate that the water in these minerals is carried to the mantle via plate tectonics:
Plate tectonics recycles Earth's crust by pushing and pulling slabs of oceanic crust into subduction zones, where it sinks into the mantle. This crust, soaked by the ocean, ferries water into the mantle. Many of these slabs end up stuck in the mantle transition zone. "We think that a significant portion of the water in the mantle transition zone is from the emplacement of these slabs," Pearson said. "The transition zone seems to be a graveyard of subducted slabs."
The Nature article is here.
Seems plausible enough, when the planet was undergoing accretion during it's youth there must have been a lot of ice floating about in space.I wonder what impact this will have on our long term climate and the future of the earth. Water on the surface currently is supposed to boil off in a billion to billion and a half years, I wonder what impact this discovery will have on that. It's also worth exploring for impact on more current climate change as water vapor is a greenhouse gas.
ReplyDeleteLet's see, Biblical literalist's claiming this as evidence of Noah's flood in 10,9,8...
Forget Bible literalists, I want to hear from Jules Verne literalists.
ReplyDeletewhy? The 20,000 leagues under the sea wasn't 20,000 leagues down it was a trip of 20,000 leagues while under the sea.
DeleteOther book.
DeleteI was stuck on the water. 250 to 410 miles underground.is a good distance from the center of the earth, there's over 3500 miles more to go form there, plenty of room for mushroom forests and dinosaurs ;-)
DeleteAnd if there is water down there, then is there life as well? (microscopically that is)
ReplyDeleteAs I understand it, this water is in the form of hydrated minerals. I don't think even an extremophile can live in that environment.
DeletePerhaps this is a bit pedantic, but the water was found in the upper mantle and transition zone about 250 to 410 miles. This is only about 10% of the way down to the center of the earth (radius 3,959 mi / 6371 km). It doesn't seem like the "core" to me.
ReplyDeleteI've often said that pedantry is quite welcome on this blog. Title amended. Tx.
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