Geomagnetism and Geoelectricity

Available Lectures: 6
Geomagnetism and Geoelectricity

Uwe Walzer

Lecture, 2 hours per week for geophysicists. An exercise of one hour
per semester week is offered.

Contents: The lecture is based on theoretical physics. Systematic
summary of the main phenomena that a theory of geodynamo has to
explain: Main field and secular variation, polarity reversals of the
geomagnetic dipole, lateral continental movements derived by
paleomagnetism. - Electrostatic fields, magnetostatic fields, Gaussian
method of surveying the magnetic field of the Earth, arrangement of
dipoles in the crust, field-parallel magnetized cylinders at various
inclinations, the aeromagnetic survey of Namibia as an example of
applied magnetics, origin of a magnetic moment from an electric
current, the nature of electrical resistance, Ampère's law, the
Helmholtz coil; magnetic properties of matter: Susceptibility,
diamagnetism, paramagnetism, ferromagnetic, antiferromagnetic,
ferrimagnetic and oblique antiferromagnetic substances, physical
background, temperature dependences, Curie temperature, influence of
oxidation on the Curie temperature , titanomagnetite series,
ilmenite-hematite series, pyrrhotite series; induced magnetization,
primary natural remanent magnetization (=NRM)(thermoremanent, chemical
remanent and sedimentary remanent magnetization), secondary NRM,
migration of single-domain distribution, origin of main geomagnetic
field: Earth's outer core, Faraday's law of induction, direct current
generator, disk dynamo, simplified representation of geodynamo, Ω -
effect, coupled disk dynamos and stochastically distributed polarity
reversals, better approximation to geodynamo, kinematic and
self-consistent dynamo theory, general theory of dynamo, anti-dynamo
theorems, theory of averaged fields, theory of functionals, Reynolds
theory, helicity, turbulence, alpha - effect; irreversible
thermodynamics and its possible application to explain the origin of
the seed field, Seebeck effect, galvanomagnetic and thermomagnetic
effects, a numerical three-dimensional convective dynamo solution with
rotating inner core and Earth´s mantle.

Suitable for: Graduate students, geophysicists, physicists, etc.

Performance record: Written exam

Reference:
Backus, G., Parker, R.; Constable, C.; 1996. Foundations of
Geomagnetism. Cambridge; Cambridge Univ. Press [1996:22]
Bergmann, L., Schaefer, C., 1987. Lehrbuch der Experimentalphysik, Bd.
2 - Elektrizität und Magnetismus. De Gruyter; Berlin, New York
[1989:83:-2]
Bergmann, L., Schaefer, C., 1987. Lehrbuch der Experimentalphysik, Bd.
6 - Festkörper. De Gruyter; Berlin, New York [1989:83:-6]
Chikazumi, S., 1997. Physics of Ferromagnetism, 2nd Edition. Clarendon
Press, Oxford [1997:8(2)]
Grant, I.S.; Phillips, W.R.; 1994 Electromagnetism. Chichester etc.;
John Wiley & Sons [1994:98(2)]
McElhinny, M. W., McFadden, P. L., 2000. Inernational Geophysics
Series, Volume 73 - Paleomagnetism - Continents and Oceans. Academic
Press; San Diego, San Francisco, New York, Boston, London, Sydney,
Tokio [R:41:73]
Merrill, R. T., McElhinny, M. W., McFadden, P. L., 1996. International
Geophysics Series, Volume 63 - The Magnetic Field of the Earth -
Paleomagnetism, the Core, and the Deep Mantle. Academic Press; San
Diego, San Francisco, New York, Boston, Sydney, Tokio [R:41:63]
Walzer, U., Begleitheft zur Vorlesung Geomagnetismus und Geoelektrizität