Sunken Worlds in Earth's Mantle: High-Res Models Challenge Current Theories

In an unexpected breakthrough, geophysicists from ETH Zurich and the California Institute of Technology discovered hidden remnants of tectonic plates deep within Earth's mantle. These remnants were found far from the expected subduction zones, where one tectonic plate typically slides beneath another.

Earthquake Waves Reveal Surprising Plate-Like Materials Deep Beneath Earth

Scientists have used seismic waves from earthquakes to study Earth's interior for years. This method allows them to gather indirect information, much like how doctors use ultrasound to examine organs inside the body without invasive surgery. When an earthquake occurs, seismic waves travel through the Earth and behave differently depending on the type of material they pass through.

By studying these waves, geophysicists can model the structure of Earth's mantle, according to PhysOrg. Traditionally, submerged tectonic plates were expected to exist in subduction zones, where one plate slides underneath another. However, the new study has revealed surprising discoveries. Researchers used a new high-resolution modeling technique to find submerged plate-like materials in regions far from plate boundaries. These anomalies appear in areas like the western Pacific and other locations deep beneath continents, where no evidence of subduction has been found.

The findings, published in Scientific Reports, challenge current theories about Earth's inner structure and the movement of tectonic plates, raising questions about how these materials got there and what they might mean for Earth's internal dynamics.

Researchers Uncover Ancient Plate Remnants Inside Earth's Mantle

The researchers used the Piz Daint supercomputer in Switzerland to carry out the analysis. According to Thomas Schouten, a doctoral student at ETH Zurich and the study's lead author, these anomalies seem much more widespread in the mantle than scientists initially thought.

One of the major surprises was finding these materials in the mantle without any geological evidence of subduction nearby. Schouten and his team speculate that the materials could be ancient remnants of tectonic plates buried deep within the Earth since the planet's formation, some 4 billion years ago, Newsweek reported. These materials could be silica-rich or iron-rich, shaped by billions of years of convection in the mantle.

The findings are baffling, as they don't fit into existing models of plate tectonics. The researchers are unsure what these anomalies are made of or how they ended up in these unexpected locations.

Andreas Fichtner, a professor of seismology at ETH Zurich, compared the situation to a doctor who, after years of examining blood vessels with ultrasound, suddenly discovers an artery in an unexpected location. This discovery suggests there is much more to uncover about Earth's internal structure.