Take a trip to the centre of the Earth

This is a short extract of an article in the ESRFnews (page 12, 13, 14).

Despite it being physically impossible to access the Earth’s core, high-pressure experiments at synchrotron sources can provide major clues about the role that iron and other materials play in the core, such as the potential presence of sulphur, silicon and oxygen. Many user groups in the field of extreme conditions come to the ESRF to try to unveil the components of the deepest area in our planet.

At the boundary between the core and the mantle there is the so-called D’’ layer. This heterogeneous layer can have from no thickness to about 250 km. The quest to decipher the strangeness of the D’’ layer could provide the community with a lot of valuable information about the Earth’s dynamics.

Closer to the surface there is the subduction zone. In this area, the reactions that take place are directly linked to earthquake and volcanic activity. Researchers are studying the different material present in the subduction zone and the dehydration processes that take place in them.

From the Earth’s core to the subduction zones, passing through the D’’ layer, everything going on inside our planet could have consequences on the surface and a better understanding of the mechanisms and composition of the Earth can help to track the possibilities of earthquakes, tsunamis, etc.

Thanks to measurements of seismic waves and studies in labs and synchrotron sources, we now have some knowledge (even if it is sometimes discrepant) about what goes on underneath our feet. Denis Andrault, a professor from the University of Clermont- Ferrand and a regular user at the ESRF, points out that: “In the last decade, the possibilities of studies in Earth sciences have multiplied thanks to technology advancements. This has made our research even more exciting and at the same time, there are more debates, which keep the field very healthy.”

Top image: The Earth as it is viewed from space. Earth ranks fifth in size among the nine planets that make up our solar system.It has a diametre of about 13000 km. Credits: NASA GODDARD SPACE FLIGHT CENTER (NASA-GSFC).