Carbon in the Earth’s core is two times less than previously believed — such data obtained in Geophysics using the model of formation of the Earth from carbonaceous chondrites. To do this, they analyzed the distribution of carbon between metal and silicate phases, which form the core and mantle, respectively, during the formation of earth’s core. Article published in the journal Proceedings of the National Academy of Sciences.
Carbon plays a significant role in the geodynamic processes, including influences on the dynamics of mantle melting and magma. In order to understand what blocks our planet was formed and how was the process of delivery and loss of carbon after its formation, the scientists model the carbon content in the soil and processes of its redistribution between the main components of magma: metal and silicate. The core consists of metallic phases, which are mainly represented by iron, Nickel and their oxides, and located in the mantle silicate phases, which are silicates of these metals with impurities — often to assess the composition of the mantle using mineral olivine.
Earth’s core is 10 percent less dense than pure metal under the same conditions. By this time it is unclear which of the light elements (silicon, oxygen, sulfur, hydrogen or carbon) makes the largest contribution to the lower density. Their presence is essential for lowering the melting temperature of iron and the formation of convection currents in the outer part of the kernel that affect the generation of the magnetic field of the Earth.
Scientists suggest that carbon makes a significant contribution to the properties of the nucleus because of its siderophyllite — affinity to the metal phase. The carbon abundance is carbonaceous chondrites, which allows considering them as the building blocks of the emerging Earth. The presence of carbon in the core as the main light element corresponds to the experimental seismic properties of the inner core.