Geology Zurich geophysicists discover unusual zones in the Earth's mantle
In an area deep below the Earth's mantle, earthquake waves behave differently than expected. According to researchers at ETH Zurich, this unexpected discovery calls into question the previous understanding of plate tectonics.
07.01.2025, 14:53
SDA
The way in which earthquake waves behave beneath the western Pacific Ocean suggests that there are remnants of a submerged tectonic plate in this zone, as the Swiss Federal Institute of Technology in Zurich (ETH Zurich) explained in a press release on Tuesday. The researchers recently published the results of their investigation in the journal "Scientific Reports".
Until now, such plates have always been discovered where they were expected, according to the university. In other words, where two tectonic plates meet and one dives under the other into the Earth's interior. This has helped scientists to investigate the formation and destruction of plates on the Earth's surface over the course of its history.
Phenomenon not yet explained
However, according to current plate tectonic theories and findings, there should be no material from submerged plates under the western Pacific. According to ETH Zurich, it is impossible that there were subduction zones nearby in recent geological history.
As the researchers can only analyze the zones indirectly via the speed of seismic waves, they cannot yet say conclusively what exactly is hidden in the Earth's mantle. In addition to the remains of tectonic plates, the researchers believe that it could also be particularly old, silicate-rich rocks that have remained unchanged since the formation of the Earth's mantle four billion years ago. Another assumption is that these are iron-rich rocks that have accumulated over long periods of time.
