"Special mechanism influencing wave propagation identified": explanation found for strange behavior of seismic vibrations deep in the earth

According to the portal "New Science", the unusual behavior of seismic vibrations that propagate at a depth of about 3,000 kilometers under the earth's crust and suddenly pick up speed at the boundary with the core, has been explained in a new scientific paper. Professor Motohiko Murakami from ETH Zurich and his research group, having reproduced the extreme conditions of the earth's interior in laboratory conditions, have identified a special mechanism that influences the propagation of these waves.

The deepest layer of the Earth's mantle, called the D" layer, is located at a depth of approximately 2,700 kilometers, just above the boundary with the planet's core. Seismologists have long noticed that at this depth, the speed of seismic waves changes dramatically, which usually indicates a transition to an entirely different type of matter. However, the cause of this phenomenon remained unsolved.

Back in 2004, Murakami found that at the boundary of the D" layer, the main mineral of the mantle - perovskite - is transformed into another form, called post-perovskite, which is capable of withstanding enormous pressures and temperatures. Initially, scientists assumed that it was this transformation that explained the acceleration of the waves. However, in 2007 it became known that a simple change in mineral structure is not enough to achieve this effect.

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