In
the remote and forested terrain of Juina in western Brazil, an ugly
rock with an uglier name surfaced months ago inside a diamond mine. It
was a tiny green crystal, all scars and bumps. It “literally look[ed]
like [it had] been to hell and back,” one scientist
said in March. But despite the provenance, the ringwoodite stone wasn’t scorched — it was, in fact, sopping wet. Providing an
unparalleled glimpse into the our planet’s innards, the stone rode a
violent volcanic eruption to the surface from 325 miles inside the
Earth’s mantle. “The eruption … is analogous to dropping a Mentos mint
into a bottle of soda,” Graham Pearson, a geochemist at the University
of Alberta,
told LiveScience. “It’s a very energetic, gas-charged reaction that blasts its way to the Earth’s surface.” It
was one of the first times anyone had seen the sponge-like ringwoodite
in anything but a meteorite or a laboratory. Formed only in conditions
of extreme pressure, it is composed of 1.5 percent water and appeared to
confirm that the Earth’s insides are very, very wet. “It translates
into a very, very large mass of water, approaching the sort of mass of
water that’s present in all the world’s ocean,”
Pearson said. Actually, according to fresh research
published in
this issue of Science, it may be substantially more than that. The
findings, researchers theorize, tell us what makes our planet blue and
suggests how the Earth formed. The oceans weren’t perhaps the product of
icy comets as
earlier research theorized, but were the result of geological and tectonic activity that drove water to the surface...
“Geological processes on the Earth’s surface, such as
earthquakes or erupting volcanoes, are an expression of what is going on
inside the Earth, out of our sight,” co-author Steve Jacobsen of
Northwestern University said in a statement.
“I think we are finally seeing evidence for a whole-Earth water cycle,
which may help explain the vast amount of liquid water on the surface of
our habitable planet. Scientists have been looking for this missing
deep water for decades.”...
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