Division I - Internal Magnetic Fields

IAGA Division I - Internal Magnetic Fields

Division I of IAGA represents a variety of research fields including planetary magnetism, geomagnetism, palaeomagnetism and rock magnetism.

Theory of planetary magnetic fields covers all theoretical aspects concerning the origin and properties of the main magnetic fields of the Earth and planets, including the geomagnetic secular variation. Current theoretical understanding is that dynamo action of motions in the electrically conducting fluid cores of planets is the main mechanism of magnetic field generation. Measurements from magnetic observatories and satellites, and knowledge of the structure, dynamics, physics and chemistry of planetary cores are used to constrain theories. Palaeomagnetic and archaeomagnetic records, together with analyses of conductivity, seismic, gravitational, rotational and heat flow data provide additional observational constraints on the terrestrial magnetic field. Computational modelling and laboratory experiments of conducting and non-conducting fluids are vital to theoretical progress.

Palaeomagnetic data provided by igneous and sedimentary rocks give access to high-resolution records of the geomagnetic field, including secular variation, palaeointensities, field reversals and the polarity time scale.

Rock- and environmental magnetism deal with fundamental magnetic properties of minerals as a function of temperature and composition, and application to problems in palaeomagnetism, environmental magnetism, biomagnetism and magnetic anisotropy. Applications include 1) how do rocks acquire and retain their magnetization for studies in palaeomagnetism and palaeointensity, 2) how does magnetic mineralogy respond to changes in environmental conditions, 3) how does the magnetic anisotropy of single minerals contribute to the anisotropy of a rock, and 4) how do magnetic particles function in the biosystem.