Open AccessA Method for Determining a Generalized Representation of Geomagnetic Field Sources
Author(s) -
Verosub Kenneth L.
Publication year - 1975
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1975.tb05489.x
Subject(s) - dipole , earth's magnetic field , spherical harmonics , geodesy , magnetic dipole , field (mathematics) , physics , geophysics , representation (politics) , geocentric model , computational physics , geology , geometry , magnetic field , mathematics , mathematical analysis , quantum mechanics , pure mathematics , politics , political science , law
Summary A new method for modelling a geomagnetic field has been developed. After the directional data has been analysed in terms of spherical harmonics, a representation of the field sources is obtained as a combination of a geocentric axial dipole and an eccentric (not necessarily axial) dipole. The free parameters are the location of the eccentric dipole and the relative proportions of the field arising from the geocentric axial dipole and from the eccentric dipole. Previous models for field source configurations are included as special cases. The new method has the particular advantage that it emphasizes the choice among models rather than the fit to a pre‐selected model. Analyses of synthetic data sets demonstrate the stability and accuracy of the method. A regionally‐averaged set of late Cenozoic palaeomagnetic data can be best represented by a combination of 75–80 per cent geocentric dipole and 25–20 per cent eccentric dipole. The eccentric component of this configuration is displaced toward the North Pacific.