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  • Article
  • Open Access

Testing the GAD throughout geological time

Earth, Planets and Space200759:BF03352732

  • Received: 20 October 2006
  • Accepted: 13 February 2007
  • Published:


The suggestion that the morphology of the geomagnetic field can be tested by inspecting the statistical distribution of palaeomagnetically-determined inclination angles has been challenged on the grounds that typical plate velocities require extremely long sampling intervals—perhaps exceeding the age of the Earth—in order to adequately sample the Earth’s surface. Here, we investigate this problem by means of a random walk model and conclude that an interval equivalent to Phanerozoic time (600 Myr) is generally sufficient.

Key words

  • Geocentric axial dipole
  • zonal geomagnetic fields
  • random walk model