- TOKYO (UPI) - A new report
from Japan Thursday reveals a vast amount of water -- up to five times
or more than in the oceans -- may hide in the molten layers of rock near
the Earth's core.
While this deep water would be locked away in crystal lattices instead
of pooling in giant underground seas, as in Jules Verne's "Journey
to the Center of the Earth," this incredible reservoir may still help
shake the foundations we stand on, making rock melt much easier and flow
significantly quicker.
"The presence of water in a crystal structure could reduce the strength
of a mineral," explained lead researcher Motohiko Murakami and his
colleagues at the Tokyo Institute of Technology in the journal Science.
The rock around the core could therefore be "considerably softened."
These findings may also explain how iridescent crystals made their way
into unusual diamonds ejected from volcanoes in Brazil.
"They're sort of a peacock color in the diamonds -- quite pretty,
actually," said diamond geologist Mark Hutchison at the Australian
National University in Canberra.
Geologists believe when Earth originally formed from dust, it should have
contained 100 times more water than now found in the oceans. While a great
deal of that may have boiled away into space early on, scientists also
suspect some of it may still lie hidden deep in Earth's interior.
Earth is split up into three distinct layers -- the thin, fractured outer
crust some 20 miles deep, the inner metal core roughly 4,300 miles wide
and the hot rock of the mantle in-between, about 1,800 miles thick.
For years, scientists have known water gets sucked from the oceans down
the cracks in the crust into the upper, shallow layers of the mantle, where
it lowers melting points and helps liquefy rock, aiding in the birth of
volcanic eruptions.
"Water is certainly being taken down -- the question is once you get
deeper in the mantle, is the water forced upwards or does it get accommodated
in the minerals of the lower mantle?" Hutchison said. "And the
answer here is that it can."
The investigators synthesized materials normally found only in the high
temperatures and high pressures near the Earth's core, such as silicate
crystals called perovskites and a black cubic mineral known as magnesiowustite.
Surprisingly, they could absorb up to two-thousandths their weight in water
-- an amount counting for five times the world's oceans.
There may be even twice that amount of water or more, if evidence from
iridescent perovskite crystals in Brazilian diamonds Hutchison found is
right. The team in Japan discovered aluminum helped perovskite absorb more
water. Hutchison believes his diamonds are from the lower mantle, and the
gems indicate aluminum levels are higher near the center of the Earth than
the Japanese researchers estimated.
Hutchison commented that while all these results say water can be down
there, "they don't answer the question if water is actually down there.
But now that we have an idea of what the maximum amounts may be, then we
can go back and tackle the question using mathematical modeling."
He explained that water at that depth could make the flow of rock -- which
affects global activity -- significantly more rapid.
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