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The amount of water entering the earth seems to far exceed that which comes out of it. (File)
According to a seismic study, the Earth drags about three times as much seawater as previously estimated, with major consequences for the global water cycle.
Seawater is caused by idle collisions of tectonic plates under the Mariana pit – the deepest oceanic trench in the world.
The trench is where the plate of the Western Pacific Ocean slides under the Mariana plate and sinks deep into the Earth's mantle while the plates converge slowly.
"People knew that the subduction zones could bring down the water, but they did not know how much water," said senior author Chen Cai, of L & 39. Washington University in St. Louis.
"This research shows that subduction zones move much more water into the depths of the Earth, many miles away than previously thought," said Candace Major, Program Director. at the Division of Marine Science of the National Science Foundation.
For the study published in the journal Nature, the team listened for more than a year to the rumblings of Earth – from ambient noise to earthquakes – to help from a network of 19 pbadive seismographs at the bottom of the ocean deployed across the Marianne. Trench, with seven seismographs based on islands.
They found that seawater at the top of the plate flowed into the earth's crust and upper mantle along the fault lines that bind the area where the plates meet and fold. Then he is trapped.
Under certain conditions of temperature and pressure, chemical reactions force water in a non-liquid form, in the form of hydrated minerals – wet rocks – which enclose water in the rock of the geological plate.
Then, the plate continues to sink deeper and deeper into the earth's mantle, dragging the water with it.
Seismic images show that the hydrated rock zone at the Marianas Trench extends 32.2 km below the study showed that the seabed was [19659004] for the region of the Mariana Trench alone, four times more subchannels than those calculated previously. These features can be extrapolated to predict conditions in other ocean trenches around the world.
Scientists believe that most of the water that falls into the trench comes back from the Earth into the atmosphere as water vapor when volcanoes move away to hundreds of kilometers.
But with revised water estimates, the amount of water entering the earth appears to greatly exceed the amount of water coming out, the researchers note.
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