Circular asymmetry of the paleomagnetic directions observed at low latitude volcanic sites
© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 1999
Received: 3 March 1999
Accepted: 12 October 1999
Published: 20 June 2014
The shape of the distribution in field directions and VGP positions was studied by Bingham statistics applied to a paleomagnetic dataset from lavas for the last 5 my by McElhinny and McFadden (1997), which includes those with VGP latitude higher than 45°. Data from Hawaii clearly show an oval shaped distribution of field directions, elongated along the meridian plane, while distribution of VGP is almost circular. Analysis on the global data divided by latitudinal bands also indicate more elongation in field directions for low latitude bands. This feature was interpreted as a general indication of dipole nature of the paleomagnetic field. For Hawaii data, however, possibility of the Pacific Nondipole Low is also suggested due to the large elongation parameter and very high significance of Fisher distribution to describe the VGP positions together with the small ASD. Although this elongated shape in the distribution of field directions is not clear for most of the individual site, the directions of the principal axes are sensitive enough to depict this feature at almost all sites.