Scientists have discovered massive mountains in the mantle of the Earth, which can change our understanding of how the planet is formed. Most students find out that the Earth has three layers: a cortex, a mantle, and a core that is subdivided into the inner and outer core.
Although this is not the case, it excludes several other layers that scientists have identified on Earth.
In a study published in the journal scientists used data from a huge earthquake in Bolivia to find mountains and other relief on a layer located 660 km straight down, dividing the upper and lower mantle.
Without having a formal name for this layer, researchers simply call it "the boundary of 660 km."
To look deeply into the Earth, scientists from the University of Princeton in the US and the Institute of Geodesy and Geophysics in China used the most powerful waves on the planet, which are generated by massive earthquakes. Earthquake data of magnitude 7.0 or higher sends shock waves in all directions that can move through the core to the other side of the planet ̵
For this study, key data was obtained from waves received after an 8.2 magnitude earthquake, the second highest ever recorded deep earthquake that struck Bolivia in 1994.
Scientists have used powerful computers to simulate complex scattering actions in deep Earth.
Technology depends on the fundamental properties of the waves: their ability to flex and bounce back.
Just as light waves can bounce off the mirror or bend (refract) when passing through the prism, waves of earthquakes travel directly through homogeneous rocks, but reflect or refract when faced with any limit or roughness. know that almost all of the objects have surface roughness and therefore light is scattered, "said Wenbo Wu, who was in Princeton during the study. surface roughness, "said Wu, who is now a postgraduate researcher at the California Institute of Technology in the United States.
"In this study, we investigated scattered seismic waves traveling within the Earth to limit the roughness of the 660-kilometer boundary of the Earth," Wu said. The researchers were surprised at how rude this limit is – more rude than the surface layer on which we all live.
"In other words, a stronger topography than the Rocky Mountains or the Appalachians, is present at a limit of 660 km," Wu said. Their statistical model did not allow to determine the exact altitudes, but there is a probability that these mountains will be larger than anything on the Earth's surface. Roughness was also not evenly distributed; just as the surface of the earth's crust has smooth ocean flooring and massive mountains, the 660-kilometer border has rough areas and smooth areas. The researchers also researched the layer 410 km down, at the top of the "transition zone" of the middle mantle, and they did not find a similar roughness. The presence of roughness at the border of 660 km has significant implications for understanding how our planet is formed and developed.