Geophysicists have discovered a 'lost world' in the Pacific Ocean

It is the discovery of a “lost world”. Underwater areas which would constitute vestiges of our planet. These spaces, until then unsuspected, would be the traces of tectonic plates, deeply submerged underwater.

This is what a team of geophysicists from the Swiss Federal Institute of Technology (ETH) in Zurich (Switzerland) discovered. In a study published in November in the journal Scientific Reports, experts report having identified the presence of rocky mantles, immersed in the Pacific Ocean, several hundred or even thousands of kilometers deep.

To make this discovery, scientists used a supercomputer, using which they were able to analyze seismic wave data accumulated by seismological stations around the world. Using this information, geophysicists were able to map the analyzed areas and create a new model of the Earth's interior, reports the American online media Futurism.

“The waves we use for the model essentially represent only one property, which is how fast they travel inside the Earth”explains Thomas Schouten, author of the study and doctoral student in geology at ETH. To identify the positioning of the rocky mantles, his team identified the «anomalies» in the speed of diffusion of these waves.

A world about which we know almost nothing

At the end of the research process, the team from the Swiss Federal Institute of Technology in Zurich was surprised to discover their results. These rocky mantles are found very far from the areas where scientists expected to find them. “Apparently, such areas in the Earth's mantle are much more widespread than previously thought”concludes Thomas Schouten.

One of these areas, discovered in the western Pacific, is particularly surprising. Based on what we know about plate tectonics, it is impossible that there was a subduction zone (sliding between two tectonic plates) nearby. His presence is then unexplained.

Other elements remain unknown in the eyes of ETH geophysicists. To date, for example, scientists do not know the composition of these recently discovered rock mantles. “It could either be ancient material, rich in silica, present since the formation of the mantle around 4 billion years ago and having survived despite the convective movements of the mantle, or areas where rocks rich in “iron accumulates as a result of these movements of the mantle over billions of years”estime Thomas Schouten.

The geology doctoral student adds: “We think the lower mantle anomalies have diverse origins.” Contrary to what was assumed until now, it is possible that these reliefs could be the result of phenomena other than plate subduction. For the moment, few certainties can be given. The research team has, to date, not drawn any conclusions about how these remains could influence the internal dynamics of the Earth.