Researchers have discovered another ocean 3 times the size of our present ocean today. But the weird thing is that this massive ocean is located under the earth surface for about 400 miles deep below that is preserve in one layer of the earth called mantle. This relates the existence of our ocean that it is came from the earth and not from the outside world. The ocean is contained within highly-pressurized rock known as ringwoodite, once it burst due to pressure in the mantle it will came out water and moved in a transition zone between 200 to 400 miles below the earth surface.
The team, led by mineralogist Steven Jacobsen, used an array of 2000 seismometers to study how seismic waves generated by earthquakes move through the Earth’s interior. The waves’ speed changed depending on the type of rock they pass through, and wet ringwoodite has a particular effect on wave velocity. Jacobsen was able to reproduce wet ringwoodite in his lab, and the group’s findings matched what he observed in the lab. As it turns out, ringwoodite, under the extreme heat and pressure of the mantle, bleeds water.
Excerpts from the findings of the team recently published in a Science journal:
The high water storage capacity of minerals in Earth’s mantle transition zone (410- to 660-kilometer depth) implies the possibility of a deep H2O reservoir, which could cause dehydration melting of vertically flowing mantle. We examined the effects of downwelling from the transition zone into the lower mantle with high-pressure laboratory experiments, numerical modeling, and seismic P-to-S conversions recorded by a dense seismic array in North America. In experiments, the transition of hydrous ringwoodite to perovskite and (Mg,Fe)O produces intergranular melt. Detections of abrupt decreases in seismic velocity where downwelling mantle is inferred are consistent with partial melt below 660 kilometers. These results suggest hydration of a large region of the transition zone and that dehydration melting may act to trap H2O in the transition zone.