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Largest subsurface body of water

Largest subsurface body of water
Who
Earth's mantle
What
4,000,000,000 cubic kilometres cubic metre(s)
Where
Not Applicable
When
12 June 2014
On 12 June 2014 US scientists revealed their discovery of water trapped within a layer of the mineral ringwoodite around 700 km deep in Earth’s mantle between the crust and the core. It was discovered by analysing seismic waves from earthquakes, which slowed down while passing through this layer, indicating the presence of water. So far this layer of ringwoodite and water has only been discovered under the continental USA and it is believed to contain around 4,000,000,000 cubic kilometres of water, some three times the volume of all the Earth’s oceans.