New Delhi, June 07: While the world is worried about impending water crisis, geophysicists in Switzerland have found the first evidence for water deep inside the earth's upper mantle. Mark Van Der Meijde and colleagues at the Swiss Federal Institute of Technology in Zurich analyzed seismic waves from below the Mediterranean Sea and believe that parts of the upper mantle could contain as much as 700 parts per million of water by weight.
Mantle is the 400 to 700 km thick region of the earth that lies below the crust and above the core. According to the report the water found in the upper mantle was released from moving oceanic plates. The Swiss team analyzed seismic waves from the plate boundary between Eurasia and Africa looking specifically for waves that were created by structures in the discontinuous regions.
They found that the region at 410 km is much wider than expected, suggesting that the widening - which is 20 to 30 km thick - is caused by the interaction of water molecules with the crystal structures in this region. Since water is believed to be related to causing deep earthquakes, the data could help researchers better understand fault mechanisms and predict earthquakes.
The team plans to look at other tectonic plate boundaries in the world to see if it can find more evidence for water at such depths. Bureau Report