The Earth is made up of several layers, two main ones, the crust and the mantle, and then the core, which is divided into an outer core and an inner core.
In addition to these four layers, Australian researchers believe they have discovered a fifth layer within the Earth’s inner core. A team of researchers from the Australian National University in Canberra published a study in the journal Nature Communications in February 2023 that indicates that the inner core could contain a metallic ball.
The scientists reached this conclusion by analysing about two hundred studies of magnitude six earthquakes that have occurred over the past decade. One of the team members, scientist Thanh-Son Pham, said the findings offer a new way to probe the Earth’s inner core and its most central region, as the study observed seismic waves that penetrate the center of the Earth before exiting at the site of the earthquake. For the first time, the observations made it possible to affirm that the seismic waves can bounce up to five times, whereas previous studies only mentioned one antipodal bounce, opposite the surface of the globe.
In particular, the study takes the example of an earthquake that occurred in Alaska and whose waves bounced in the South Atlantic Ocean before returning to Alaska. The researchers believe that this internal core could help to reconstruct the mystery of the formation of the planet, even if many questions remain to be clarified concerning the internal part of the earth’s layer.
For the moment, the analysed data only allow supposing that a major phenomenon could have substantially modified the coating of the inner core. The hypothesis presented by the Australian researchers in the study could help to deepen the knowledge of earthquakes, although it remains to be validated.
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