Physico-chemical processes occurring in the Earth's deep interior are responsible for many phenomena that can be observed at the Earth’s surface, such as geologic activity and the presence of a magnetic field, just to mention a couple. It is thus fundamental to understand the Earth's internal structure and dynamics, and to quantify the mass-energy exchanges between the metallic core, the silicate mantle, and the lithospheric plates. One of the strengths of the research done within IPGP is that it couples challenging experimental studies and computational modeling to a wide range of observations that include, but are not limited to, geophysics, geochemistry and geology. This integrated approach is essential to interpret the present-day state of the Earth's interior, as revealed by geochemical and seismological observations, and by measurements of the Earth's potential fields.
An understanding of the present-day state is also fundamental to constrain the way our planet evolved over geological times through key processes such as global scale plate motions, convective cooling, thermochemical mixing and differentiation. Last but not least, the direct involvement of IPGP in planetary missions (e.g., InSight, which will provide the first seismic data on Mars), also opens the way to the vast research field of comparative planetology.
Five major questions in this field have been identified:
• Which reactions and chemical exchanges occur at high P-T conditions between inner and outer core? How can one constrain the amount of energy available to power the geodynamo?
• Can one predict present and future variations of the magnetic field by using cutting-edge magneto-hydrodynamic simulations of the Earth's geodynamo?
• How does mantle convection affect long-term mixing of chemical heterogeneities, fluxes of volatiles, and the thermal evolution of the planet? Is the mantle ingazing or outgazing?
• Continental rifting, passive margins and spreading ridges: how are lithospheric processes related to the underlying mantle?
• What can one learn from the future observations of the InSight spatial mission, beyond revealing the internal structure of Mars?