Deep mantle water

Deep in the Earth’s mantle is an underground water reservoir at least the volume of the Arctic Ocean.

Analyzing the way waves damp out from their source, seismologists measure how stiff a region is – a function of how hot it is and how much water it contains.

Beneath Asia, where the ocean floor is sinking down into the earth, the fallen Pacific sea floor piles up at the base of the mantle.

Water inside the rock goes down with the sinking slab and it’s quite cold, but it heats up the deeper it goes, and the rock eventually becomes unstable and loses its water. The water then rises up into the overlying region, which becomes saturated with water.

“If you combine the volume of this anomaly [the so-called Beijing Anomoly] with the fact that the rock can hold up to about 0.1 percent of water, that works out to be about an Arctic Ocean’s worth of water.”

Seventy percent of the earth is covered by water, which is very important for the earth’s geology, serving as a lubricant that allows efficient convection and plate tectonics and the continental collisions that form mountains. [story at Science blog]

There are other data showing the potential for large bodies of water much closer to the surface. For many years there have been murmurs that plans are underfoot to develop a major freshwater source underneath an area near the city of Reno, Nevada. At one time the claims exceeded a five to seven mile depth over a length exceeding 300 miles. I worked with Frank Emery Cox in a somewhat informal organization known as Nevada International Trade Exchange (N.I.T.E.) that took a forward view that Nevada would benefit after developing deep water sources rather than stretching its river and surface assets to their limits. Frank developed the aluminum curtain wall in the 1940’s and made a career developing the feasibility of more than 1,500 shopping centers over his long life.

Water, indeed, comes from rock?
Drilling the world’s deepest hole at the Kola Peninsula, about 7 miles deep, scientists in the USSR found to their surprise that deep rock was saturated in water – trapped inside the structure of rock itself!