American geologists from Arizona State University have discovered that the Earth’s surface waters can penetrate deep into the planet and transform the outer layer of its core. The study was published in the scientific journal magazine Natural Geology.
Scientists have found that the water has become deeper due to the movement of tectonic plates over billions of years. Reaching the core-mantle boundary about three kilometers from the surface, the liquid causes deep chemical interactions that change the structure of the core.
This reaction forms a hydrogen-rich, silicon-poor layer, transforming the outermost region of the core into a film-like structure. In addition, the process produces silica crystals that rise and integrate with the mantle.
According to calculations, this modified liquid metal layer will be less dense and its seismic velocities will decrease.
“For many years it was thought that there was little exchange between the Earth’s core and mantle. But our recent experiments at high pressure tell a different story. We found that when water reaches the core-mantle boundary, it reacts with silicon in the core to form silica,” said lead author Dan Shim.
The discovery expanded scientists’ understanding of Earth’s internal processes and pointed to a more extensive global water cycle than previously thought. The altered core “film” affects geochemical cycles that link the surface water cycle to the deep metal core.
Previous scientists I learnedMars is said to have a layer of molten rock inside it.