Convective Mixing in magma chambers

• Applicant: Professor Dr. Henri Samuel
• Subject Area: Geophysics
• Term: from 2011 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 204178230

While geochemical observations strongly suggest that Earth’s mantle is heterogeneous at all scales, the cause of such heterogeneity remains debated and depends on the ability of mantle motions to create, preserve or to erase heterogeneities. As errupted mantle material is processed through magma chambers, understanding the efficiency of mixing processes in this context is fundamental to interpret surface geochemical observations.We therefore propose to study and to quantify systematically the efficiency of convective stirring and mixing in magma chambers. We will model the dynamics of crystal-bearing magmas using three-dimensional numerical modeling at both infinite and finite Prandtl numbers, for various Rayleigh numbers. To this end we will use state-of-the-art methods to account for the interactions between crystals of various densities and low viscosity melts in laminar or turbulent regimes, using either Direct Numerical Modeling or Large Eddy Simulations. We will apply various complementary techniques for studying stirring processes and to quantify their efficiency. In addition, we will derive simple laws to express stirring time as a function of the governing parameters and the wavelength of heterogeneity.

• DFG Programme: Research Grants
• International Connection: France