News Excerpt:

Scientific news about a massive ocean hidden under the Earth's crust has gained traction on social media.

Key highlights of the findings:

• The water is stored 700 kilometres below the surface of the Earth in a rock known as ringwoodite.
• This subterranean reservoir is three times the volume of all the planet's surface oceans combined.
• Ringwoodite is like a sponge soaking up water; there is something very special about the crystal structure of ringwoodite, which allows it to attract hydrogen and trap water.
• Researchers made the discovery after studying earthquakes and discovering that seismometers were picking up shockwaves under the surface of the Earth.
• 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 and melting of vertically flowing mantle.
• They also found intergranular melt in the transition zone. 
• 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.

Importance of research:

• This discovery potentially reshapes our understanding of Earth’s water cycle. It proposes that water may exist within the mantle, migrating amid rock grains.
• It can play a major role in maintaining water beneath the Earth’s surface, without which water would predominantly reside on the planet’s surface, rendering only mountain peaks visible.