651-4017-00L  Earth's Core and the Geodynamo

SemesterSpring Semester 2021
LecturersP. D. Marti, C. Hardy
Periodicityyearly recurring course
Language of instructionEnglish


AbstractIn Earth's core, motions of liquid iron act as a dynamo producing the geomagnetic field. This course explores the composition, structure and physical conditions in Earth's core and describes the geomagnetic field before focusing on the geodynamo mechanism. An interdisciplinary perspective is adopted involving electromagnetism and fluid dynamics but also seismology and mineral physics.
ObjectiveThe objectives of this course are:
(i) Development of the geophysical and sometimes mathematical tools
needed to understand Earth's core and the geodynamo.
(ii) Acquisition of knowledge concerning physical and observational constraints on the dynamics of Earth's core and the evolution of the geomagnetic field.
Content(i) Structure and composition of Earth's core: Including PREM, Adams-Williamson equation, Inner core anisotropy, Geochemical constraints, High Pressure mineral physics Experiments, Phase changes, Adiabatic temperature profiles, Geotherms, Power sources for the Geodynamo.
(ii) Observational geomagnetism: Spherical harmonics, Global field models, Westward drift, Jerks, Core field inverse problem, Core field structure and historical evolution, Polarity excursions and reversals, Time-averaged field.
(iii) Theory of the Geodynamo: Review of Maxwell's equations, Induction equation, Alpha Effect and Omega Effect, Proudman-Taylor theorem Geostrophy, Rotating Convection, Experimental and numerical dynamos.
Prerequisites / NoticeThe Earth's Core and Geodynamo Course capitalizes on the knowledge of:
- 651-4001-00L: Geophysical Fluid Dynamics
- 651-4130-00L: Mathematical Methods
Therefore we recommend that the students have attended those courses or others of similar content.