Some of Earth’s Surface Water Might Be Traveling Down to the Outer Core

An international team including researchers from Arizona State University’s school of Earth and Space Science just published a paper in Nature Geoscience detailing that Earth’s surface water may penetrate deeper into the planet that previously expected. This research provides new insight into chemical interactions at the core-mantle boundary and our global water cycle, and builds on previous research done by the same team.

Image of Earth taken from the International Space Station by astronaut Reid Wiseman on September 2nd, 2014. Credit: NASA/Reid Wiseman.

High Pressure Experiments

Researchers behind the paper published in November used high pressure experiments at the Advanced Photon Source of Argonne National Lab in Illinois and Germany’s PETRA III of Deutsches Elektronen-Synchrotron to replicate the extreme conditions around Earth’s core.

In their experiments, they tested how surface water at the mantle-core boundary would react to the extreme heat and pressure around the core. What they found was that the water chemically reacted with core materials, forming a hydrogen-rich, silicon-depleted layer that acted like a film surrounding the outer core. The reaction also forms silica rich crystals that rise into the mantle. This results in a dense, silica rich area at the bottom of the mantle. The findings of the experiments gave geologists answers about a mysterious layer of Earth’s interior…