Earth’s Core Unveils a Hidden Layer Molded by Surface Water

Earth’s Core Unveils a Hidden Layer Molded by Surface Water

A new study by an international team of researchers, including those from Arizona State University (ASU), has uncovered a surprising link between Earth’s surface and its innermost core. The study, published in Nature Geoscience, reveals the formation of a distinct layer, known as the E prime layer, at the outermost part of the planet’s core, attributed to surface water penetrating deep into the Earth over billions of years.

Earth’s interior comprises four primary layers: an inner core at its center, surrounded by the outer core, mantle, and crust. For years, scientists believed that material exchange between the core and mantle was minimal. However, this latest research suggests that tectonic plates have transported surface water deep into the Earth, reaching the core-mantle boundary about 1,800 miles below the surface.

Upon reaching this boundary, the water undergoes a significant chemical reaction with the core’s silicon, forming silica. This reaction leads to the formation of a hydrogen-rich, silicon-depleted layer at the outer core, resembling a film-like structure. Silica crystals generated by this process ascend and blend into the mantle, affecting its overall composition.

The researchers observed that subducted water reacts chemically with core materials under high pressure, using advanced experimental methods at the Advanced Photon Source of Argonne National Lab and PETRA III of Deutsches Elektronen-Synchrotron in Germany. These techniques aimed to recreate the extreme conditions observed at the core-mantle boundary.

The discovery of the E prime layer and its formation by surface water has significant implications for our understanding of Earth’s internal mechanisms. It suggests that the core and mantle are not isolated systems but interact with each other through the movement of materials and fluids. This interaction plays a crucial role in shaping the Earth’s magnetic field, generating heat, and driving plate tectonics.

The study also raises the possibility that water may be present deeper within the Earth’s core. Further research is needed to explore this possibility and unravel the full story of Earth’s hidden water reservoir.