Strange bubbles deep within the Earth are intriguing scientists

Spots resembling tectonic plates are in places scientists never expected to see them. They may be old material.

A team from the University of Zurich used the supercomputer Piz Daint to process data from all types of seismic waves that our planet emits, says .

They then drew a much more precise map of its lower mantle than had been previously available.

But as they did so, they found huge patches resembling giant tectonic plates spread across the entire planet. They are huge patches of rockcooler and of greater density than the surrounding lower mantle.

In the western Pacific Ocean, among other places, there are subduction zones (places where one lithospheric plate sinks beneath another).

But, in the case of these spots, they are far from these known subduction points, so scientists cannot say with certainty what they are.

“Apparently, these zones in the Earth’s mantle are much more disseminated than previously thought”, says the geoscientist Thomas Schoutenmain author of , published in Nature in November.

But the origins of these mysterious “bubbles” may go beyond subduction, the researcher guarantees.

“We have to calculate the different material parameters that can generate the observed speeds of different types of waves. Essentially, we have to delve deeper into the material properties which is behind the speed of the wave”, he states.

“It could be ancient material, rich in silica, which has existed since the formation of the mantle, around 4 billion years ago, and that has survived despite convective movements of the mantle, or areas where iron-rich rocks accumulate, as a result of these mantle movements over billions of years”, further suggests Schouten.

In any case, further investigation is needed to understand what these strange bubbles are, how they got there and what they could imply for the understanding of planet Earth.