Deep Earth Interior
Our broad picture of the Earth's deep interior is that it is approximately a sphere made up of a solid inner core immersed in a fluid outer core, both of them being mainly constituted of iron. The outer core, with a radius of approximately 3480 km, is itself surrounded by the mantle, whose main constituents are silicates. At short timescales, say from a fraction of a second up to years, the mantle deforms as a solid body, allowing for the propagation of seismic shear waves. At very long timescales, the mantle is convecting as a viscous fluid. Analysis of geochemical, seismological, geodetic, geomagnetic, and other geophysical data, coupled to theoretical and numerical modeling, of course provide a much more refined description of the dynamics and structure of the Earth's interior. Departures from spherical symmetry, couplings between the inner core, outer core and mantle, chemical composition, solidification of the outer core leading to the growth of the inner core, thermodynamics over a large range of timescales, generation of the magnetic field, or heat generated by radioactive elements are only but a few of the topics studied nowadays by the community of scientists interested in the Earth's deep interior. Within the framework of a LIA, we wish to connect distinct domains of geophysics and geodesy - global geodynamics, long-period seismology and Earth rotation.
There will be four sub-axis allowing dealing with:
(1) High resolution imaging of deep structures by full waveform inversion;
(2) Imaging of seismic anisotropy;
(3) Constraining the Earth's structure and dynamics (normal modes data of the core)
(4) Computational geodynamics and seismic attenuation in the crust