I wonder how accurate the estimated amount is.
Its says enough water to fill our oceans three times over, so would this have meant at some time our oceans were vastly deeper or would the entire surface of the Earth been different to accomodate all the water.
http://www.news.com.au/technology/environment/amazing-ocean-discovered-trapped-underneath-north-america/story-fnpjxt8n-1227137237351
A MASSIVE rock layer located hundreds of kilometres below the Earth’s surface contains a vast underground ocean trapped by pressure and blazing hot temperatures.
The discovery, by researchers from Northwestern University and the University of New Mexico and published inScience last week, reveals the massive reservoir of water could contain enough water to fill our oceans three times over.
But the water isn’t the ordinary kind we’re used to seeing, drinking or swimming in.
In fact it’s neither liquid, frozen or of a vapour variety, but instead remains trapped in the molecular structure of mantle rock by huge amounts of pressure and temperatures up to 1100C.
The ‘ocean’ is believed to exist in what scientists are call a “transition zone” in Earth’s mantle rock, about 400 to 660 kilometres below the surface.
North-western geophysicist Steve Jacobsen and University of New Mexico seismologist Brandon Schmandt found deep pockets of magma located beneath North America and say the finding could represent Earth’s biggest water reservoir.
Their discovery indicates water from the Earth’s surface can be driven to huge depths by factors such as plate tectonics, which could cause partial melting of the rocks found deep in the mantle, Phys.org reported.
Their findings could also help scientists learn more about how our Earth was formed.
They made the discovery using seismometers to measure the seismic waves generated by hundreds of earthquakes with the waves detected at the surface as they made their way below.
According to the Huffington Post’s Jacqueline Howard rocks at this depth have a pretty amazing capacity to store water.
Howard reveals prior to the researchers’ discovery scientists previously thought mantle was mainly made up of molten rock or magma.
“The mantle is also where molten rock known as magma can form before it flows upward during volcanic eruptions — at which point the magma becomes lava,” she explains.
“This was pretty much the picture scientists had of the mantle until earlier this year-when a vast hidden ocean of water was discovered some 400 miles (643km) beneath North America.”