Between the core and Earth’s mantle is a “vast structure made of dense material”, the existence of which was not previously known. The finding was made by a group of scientists from the University of Maryland (USA). The recording was made thanks to an investigation into the behavior of seismic waves. The team used the same algorithm that is applied to analyze distant galaxies, according to an article published in the journal Science . The discovered structure is found below the Marquesas islands in the South Pacific, which are volcanic in type. Furthermore, the structure underneath those Hawaiian islands was shown to be much larger than previously believed.
The researchers don’t yet know what this finding is made up of, but they point out that “it provides an opportunity to better understand the intricate processes that have allowed our planet to evolve and change over time.” ” By looking at thousands of echoes from the central mantle boundary at the same time, rather than focusing on a few at a time, as is often done, we have gained a whole new perspective ,” said Doyeon Kim, a postdoctoral fellow in the Department of Geology. and main author of the article.
According to the scientist, her study shows that the boundary region of the core-mantle has many structures that can produce these echoes. Her team measured the travel time and amplitude of the echoes generated by the seismic waves after an earthquake. Thanks to these calculations, the researchers developed models of the physical properties of rocks hidden below the surface, among other things.