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Note: this topic is from April 23, 2002. The Earth oozes hydrocarbons and water:

Earth could hold more water
by Philip Ball
8 March 2002
There is already thought to be several oceans' worth of water slightly higher in the mantle, at a depth of around 400-650 km. This region is called the transition zone, as it is between the upper and the lower mantle. The lower mantle's minerals can retain about a tenth as much water as the rocks above, Murakami's team finds. But because the volume of the lower mantle is much greater than that of the transition zone, it could hold a comparable amount of water... Any hydrogen in the rocks presumably comes from trapped water, an idea that other measurements support. The researchers found more hydrogen than previous experiments had led them to expect.
Inner Earth May Hold More Water Than the Seas
by Ben Harder
March 7, 2002
Based on what they witnessed in their lab, the researchers concluded that more water probably exists deep within the Earth than is present on Earth's surface -- as much as five times more... Murakami and his colleagues reached their conclusion based on how much water they managed to dissolve under the experiment's extreme conditions in several types of material that make up much of the lower mantle. They used heat and pressure -- 25.5 gigapascals of it, or more than 250,000 times natural atmospheric pressure at sea level -- to create four mineral compounds that exist in the lower mantle... Earth's oceans make up just 0.02 percent of the planet's total mass. T his means the vast lower mantle could contain many times more water than floats on the planet's surface.




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