Researchers affiliated with the University of Maryland conducted, in premier, an analysis of hundreds of earthquakes in order to identify echoes from features located deep inside our planet. Geophysicists have analyzed thousands of recordings of seismic waves, which are actually sound waves travelling through the crust of the Earth. The purpose of this is to identify the echoes from the boundary situated in between the Earth’s molten core and the solid mantle that lies right above it. These echoes are actually more widespread, heterogeneous structures, which are areas of very dense rock of a high temperature.
Researchers are not yet sure about the composition of these structures. Some studies performed in the past have provided a more limited view of the structures. In order to uncover the geologic processes that are going on inside our planet, scientists must first understand the extend and the shape of these mantles. This knowledge might lead to clues about the workings of plate tectonics and the evolution of Earth itself.
New studies provide the first comprehensive view of the core-mantle boundary over a large area with an incredibly high resolution. The study was published in the academic journal Science on June 12, 2020.
Scientists have focused on echoes of seismic waves traveling underneath the Pacific Ocean basin. The analysis has showed a previously unknown structure beneath the volcanic Marquesas Islands, located in the Southern Pacific. This shows that the structure beneath the Hawaiian Islands is a lot larger than scientists initially believed.
Doeyon Kim, a postdoc affiliated with the UMD Department of Geology, has explained that looking at the echoes of multiple core-mantle boundaries, instead of looking at just one at a time, has given the researchers a much better perspective. Kim has also stated that this shows that the core-mantle boundary region has plenty of structures that are able to produce echoes, which is something that the researchers did not realize before.