Geomagnetic Field as Recorded in the Mt Erebus Volcanic Province: Key to Field Structure at High Southern Latitudes

Paleomagnetic data (directions of ancient geomagnetic fields obtained from rocks) play an important role in a variety of geophysical studies of the Earth, including plate tectonic reconstructions, magnetostratigraphy, and studies of the behavior of the ancient geomagnetic field (which is called paleo-geomagnetism).

Over the past four decades the key assumption in many paleomagnetic studies has been that the average direction of the paleomagnetic field corresponds to one that would have been produced by a geocentric axial dipole (GAD) (analogous to a bar magnet at the center of the Earth), and that paleoinclinations (the dip of magnetic directions from rocks) provide data of sufficient accuracy to enable their use in plate reconstructions.