ABSTRACT
By the end of this chapter, we will have described the Earth’s interior in terms of structure and composition as presently known and shown on figure 1. It can be briefly described as consisting of an outer silicate solid shell, the mantle, and an inner core mostly made of Fe. The core itself is divided into a liquid outer part and a solid inner part, its radius is about half the Earth’s radius. The relative abundance of geophysical data (geodetic, seismic) gives us a much more precise picture of the Earth’s interior compared to other planets. In addition to geophysical data, a wealth of information comes from the petrological and geochemical studies of rocks, especially regarding the time evolution of the planet. Knowledge of Earth’s interior can indeed not be dissociated from that of the history of the Earth, including its accretion, its differentiation into the main reservoirs (atmosphere, crust, mantle and core), and up to its present state and dynamics. Table 1 summarizes what needs to be measured to solve those questions.
