Since January 2011, the PI holds a faculty position at the Collège de France, this proposal will facilitate transferring and re-establishing her research program at IPG in Paris. The goal of the proposed research program is to investigate earth’s deep structure and dynamics using advanced seismological forward and inverse modeling techniques. The primary focus is on global and continental scale mantle structure, with a secondary focus on the earth’s core. The primary objective is to develop high resolution three-dimensional models of the present day thermal and compositional structure of the mantle through the development of forward and inverse seismic waveform modeling approaches. This will be pursued along two directions that will eventually be combined: (a) Using a spectral-element-based seismic waveform modeling approach, develop high resolution seismic models of 3D elastic, isotropic and anisotropic , and anelastic structure of the earth’s mantle, with particular emphasis at the global scale on the lower mantle and, at the tectonic plate scale, on lithosphere-asthenosphere structure; (b) Develop an approach to invert full seismic waveforms, combined with other seismic constraints (such as travel times and normal mode eigenfrequencies) directly for 3D thermal and compositional structure of the mantle, using the best available constraints from mineral physics and geodynamics. A secondary objective is to constrain inner core structure and anisotropy using a combination of free oscillation splitting measurements and travel times and amplitudes of inner core sensitive body waves, with the goal of better characterizing the mantle versus inner core origin of observed anomalies currently attributed to inner core anisotropy.