Open AccessSpherical Harmonic Analysis of Palaeomagnetic Inclination Data *
Author(s) -
Georgi Daniel T.
Publication year - 1974
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.1974.tb05439.x
Subject(s) - declination , gauss , geodesy , geology , spherical harmonics , harmonic analysis , intensity (physics) , geometry , geophysics , mathematics , mathematical analysis , physics , optics , astronomy , quantum mechanics
Summary A method for determining the relative values of the low‐order Gauss coefficients for the palaeomagnetic field from inclination data only, i.e. in the absence of declination and intensity information, has been used to extend the analysis carried out by Creer, Georgi & Lowrie to include the core data published by Opdyke & Henry. The 20 regional average Quaternary palaeomagnetic inclination directions given by Creer et al. were combined with 12 new regional average data points derived from the deep‐sea sediment core data published by Opdyke & Henry to form a grand population of 32 inclination directions. The analysis was carried out to determine both the second‐order and third‐order coefficients. It was found that the normalized amplitudes of the second‐and third‐order terms dropped off at least as rapidly as those of the present‐day field. The Cartesian co‐ordinate positions of the eccentric dipole for the grand populations were found to be in general agreement with those found by Creer et al. The input data were also perturbed to determine the sensitivity of the offsets to errors in the data. It was generally found that the offset along the rotation axis was least affected by input errors.