is the normalized Euler frequency (in units of reciprocal years), C {{= 8.04 × 10³⁷ kg m²}} is the polar moment of inertia of the Earth, A is its mean equatorial moment of inertia, and C - A {{= 2.61 × 10³⁵ kg m²}}.

The observed angle between the figure axis of the Earth F and its angular momentum M is a few hundred milliarcseconds (mas). This rotation can be interpreted as a linear displacement