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Geomagnetism and Geoelectricity

Class at Faculty of Mathematics and Physics |
NGEO080

Syllabus

* Geomagnetic field

Historical introduction. Measurements. Magnetic and geomagnetic coordinates.

Geomagnetic maps. Mathematical description --- the Gauss spherical harmonic analysis. Internal and external fields. Geomagnetic dipole, excentric dipole.

Paleomagnetism. Magnetization. Inversions. Virtual and paleomagnetic poles.

Polar wandering, relations to plate tectonics.

* Introduction to dynamo theory

Dynamo principle. Bullard's disk dynamo. Equations of geodynamo. Kinematic and dynamic dynamo theory. Alfvén's theorem. Magnetic Reynolds number. Cowling's theorem. Alfa and omega effects. Numerical models of geodynamo.

* Magnetic fields of solar system bodies

Sun and its structure, Solar magnetic field and its time variations. Solar wind.

Magnetic fields of planets.

* Short-term vairations of external field

Magnetosphere and ionosphere. Movements of charged particles in EM field.

Regular variations. Magnetic storms and substorms. Polar lights. Pulsations.

Geomagnetic indeces.

* EM induction in the Earth and electrical conductivity

Basic principles. Penetration depth. Magnetovariational and magnetotelluric soundings. Transfer functions. Electrical conductivity of the Earth's mantle, 1-D and 3-D models. Secular variations, geomagnetic jerks, and electrical conductivity of the lower mantle. Core-mantle coupling.

Annotation

Measurements of geomagnetic field and its mathematical description.

Paleomagnetism. Introduction to dynamo theory. Magnetic fields of solarsystem bodies. Short-term geomagnetic field variations and electrical conductivity of the Earth.