The Earth's equatorial principal axes and moments of inertia.
Abstract
Let the Earth's equatorial principal moments of inertia be A and B, where A < B, and the corresponding principal axes be a and b. Explicit formulae are here derived for determining the orientation of a and b axes and the difference BA using C_{22} and S_{22}, the two gravitational harmonic coefficients of degree 2 and order 2. For the Earth, the a axis lies along the (14.93°W, 165.07°E) diameter, and the b axis lies perpendicular to it along the (75.07°E, 104.93°W) diameter. The difference BA is 7.260x10^{6}MR^{2}. These quantities for other planets are contrasted, and geophysical implications are discussed.
 Publication:

Geophysical Journal International
 Pub Date:
 September 1991
 DOI:
 10.1111/j.1365246X.1991.tb06341.x
 Bibcode:
 1991GeoJI.106..699L
 Keywords:

 Earth Axis;
 Earth Rotation;
 Moments Of Inertia;
 Axes Of Rotation;
 Equatorial Regions;
 Gravitational Fields;
 Earth: Moments of Inertia