This paper examines the problem of assessing the current influence of large lithospheric plates on the planet’s rotational regime. For each plate, the components of the inertia tensor are calculated using exact analytical integrals in spherical polar coordinates. From the law of conservation of angular momentum, the change in angular velocity and the angle of rotation axis displacement are derived . An analytical assessment is carried out for the three largest plates – the Pacific, Eurasian and North American plates – using the integrated average parameters of the global models CRUST1.0 and LITHO1.0 and the polygonal plate boundary model PB2002. It is shown that the individual static inertial contributions of the plates are of the order of ~10⁻⁹–10⁻⁸ and ~10⁻⁴–10⁻² angular seconds, which is two to three orders of magnitude smaller than the effects of glacial isostatic rebound (GIA), but is a necessary fundamental factor in the formation of the total polar wobble. A practical algorithm for performing calculations based on open-access datasets is described.
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