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“In the six hundredth year of Noah’s
life, in the second month, the seventeenth day of the month, the same
day were all the fountains of the great deep broken up.” Genesis 7:11
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GEOLOGY
– A reservoir of water lying deep under the Earth’s surface may contain
triple the volume of every one the world’s oceans and may even be the
“wellspring” source of them, U.S. researchers say. Although not in a
liquid form most familiar to all of us — it is instead bound within
rocks deep in the Earth’s mantle — it likely represents the largest
reservoir of water on Earth, scientists at the University of New Mexico
and Northwestern University say. Writing in the journal Science, they
report finding pockets of melted magma 400 miles underneath the North
American continent that are likely signatures that water exists at those
depths. Scientists have long questioned whether the mantle, the rocky,
hot layer between the Earth’s crust and its core, might contain water
bound up and trapped within rare minerals. The new discovery is evidence
water can be transported from the surface of the Earth to great depth
by plate tectonics, the movement of continents and plates over the
Earth’s 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,” says geophysicist and study
co-author Steve Jacobsen at Northwestern. “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.”
Movement and partial melting of rocks in the mantle’s transition zone — a
region between the mantle’s lower and upper layers from around 250 to
400 miles deep — could allow water to become tightly bound to the
minerals there, the researchers said.
To test if the transition zone could be
a possible deep water reservoir, the researchers used seismic waves
recorded during earthquakes to analyze the structure of the mantle in
the zone and to detect if melting is taking place as tectonics drives
rocks ever deeper. “If we are seeing this melting, then there has to be
this water in the transition zone,” University of New Mexico
seismologist Brandon Schmandt says. “Melting is just a mechanism of
getting rid of the water,” he says. If the surface water the Earth
possesses today came from such degassing of molten rock, the researchers
say, that’s in contrast to the theory held by some scientists that
water came to a young Earth by way of large, icy comets. It is of course
the existence of liquid water on the surface of the Earth that makes
our planet habitable and capable of supporting life, which is why its
origin is of such interest to science. The latest findings are strong
evidence of a process where water has long been cycling between deep
interior reservoirs and the surface through the action of plate
tectonics, the researchers say. “Scientists have been looking for this
missing deep water for decades,” Jacobsen says. And they may just have
found it. –
Tech Times
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