Water has leaked into Earth's core. Scientists reveal mysterious makeover

Water has leaked into Earth’s core. Scientists reveal mysterious makeover

For decades, a thin layer just over a few hundred kilometers thick at the boundary of Earth’s core has puzzled scientists. They call it the enigmatic E prime layer.

However, new research led by an international team has shed light on this deep Earth mystery. The findings, published in the journal Nature Geoscience, reveal that Earth’s surface water can travel to great depths, significantly altering the composition of the outermost part of the planet’s liquid metallic core.

The planet has three layers crust, mantle and core.

The study indicates that for billions of years, water has been leaking deep into the Earth’s interior by tectonic plates. When this water reaches the core-mantle boundary, approximately 3,000 kilometers beneath the surface, it induces a significant chemical reaction with the core materials.

Through high-pressure experiments, the researchers discovered that the interaction between subducted water and the core results in a hydrogen-rich, silicon-depleted layer. This transformation creates a film-like structure at the top of the outer core and leads to the formation of silica crystals that ascend into the mantle.

These changes are expected to make the liquid metallic layer less dense and alter its seismic velocities, which aligns with the anomalies previously detected by seismologists.

Dan Shim, one of the lead researchers, explained the significance of their discovery: “For years, it has been believed that material exchange between Earth’s core and mantle is small. Yet, our recent high-pressure experiments reveal a different story. We found that when water reaches the core-mantle boundary, it reacts with silicon in the core, forming silica.”

This revelation not only challenges the long-standing belief about the limited interaction between the core and mantle but also suggests a dynamic core-mantle relationship with substantial material exchange.

The implications of this research extend beyond the scientific community, as it proposes a more complex global water cycle than previously thought and underscores the interconnectedness of geochemical processes from the surface to the core.

To achieve these insights, the team employed sophisticated experimental techniques at two major facilities—the Advanced Photon Source of Argonne National Lab in the United States and PETRA III of Deutsches Elektronen-Synchrotron in Germany. These methods allowed them to replicate the extreme conditions found at the core-mantle boundary, leading to their remarkable findings.

The study not only unravels the mystery of the E prime layer but also enhances our comprehension of Earth’s internal mechanisms, offering a new perspective on the planet’s deep-water cycle and its impact on geochemical cycles.

This research marks a significant step forward in our understanding of Earth’s inner workings and could have far-reaching effects on future studies of planetary science.