Chinese Researchers Reveal How Earth's Deep Mantle Stored Oceans Of Water Billions Of Years Ago

Chinese researchers have uncovered a key mechanism explaining how Earth may have stored large amounts of water in its early history. Their study sheds new light on how the planet transformed from a fiery ball of magma to the life-supporting world we know today. Researchers at the Guangzhou Institute of Geochemistry, a subsidiary of the Chinese Academy of Sciences, have demonstrated through experiments that Earth's deep mantle could have served as a vast water reservoir more than 4 billion years ago. The study was published in the journal Science, reported CGTN.

The journal's editorial summary highlights the mystery of what happened to the water when Earth's early magma oceans crystallised, especially in the deep mantle layers.

The key mystery of this discovery is bridgmanite, the most common mineral in the lower mantle. Previously thought to have only limited water-storage capacity, researchers found that bridgmanite possesses temperature-dependent capacity and can effectively trap water molecules.

The researchers recreated the extreme conditions of the lower mantle-high pressure and temperatures of approximately 4,100 degrees Celsius-using a diamond anvil cell and laser heating.

The study revealed the surprising finding that the higher the temperature, the better bridgmanite is at trapping and storing water when it forms from cooled magma. 

This process may have stored enough water in the solid mantle to be equivalent to 0.08 to 1 times the volume of today's oceans.

Over billions of years, this initial water slowly returned to the surface through volcanic activity, helping to create a blue and habitable planet.

This discovery makes a significant contribution to understanding Earth's early evolution and the role of deep mantle minerals in maintaining life-supporting conditions.