Changes of Velocity of Rotation of the Earth, its Figure's Deformation and Long-period Nutational-Precessional Movements of the In-stantaneous Pole of Rotation

Abstract

It is shown, that continuous changes of angular velocity of rotation of the plas-tically-elastic Earth should cause the continuous coupled deformation of a crustal layer with redistribution of masses in a sub-crustal layer, and also, as conse-quence of these phenomena, a polar pulsation of figure when polar diameter of the Earth increases and decreases with time. The mechanism of occurrence of de-formations of the planet body under action of the deforming (centrifugal) variable force is found, and the equations of balance are deduced. The calculations have given the quite real changes of compression and radial displacements of the Earth's crust and its other shells. The opposite process is also shown, namely: observed fluctuations of amplitude of the polar compression quite correspond to real fluctuations of duration of a day. The influence of the rotational regime on re-al long-period nutational-precessional motions of the instantaneous pole of the Earth's rotation is considered. The observed 12-month oscillations of the instan-taneous axis of rotation are explained by the influence of the variable centrifugal force causing deformation of the figure that is not uniform in different longitudi-nal zones, without involving the baric-circulational processes as an intermediate link. Thus, both 14-month free (Chandler) and forced 12-month fluctuations of the pole location are considered from a single point of view - as a result of the variability of the rotational regime of the Earth. The analysis of heliogeophysical data for 1900-2017 confirms the validity of the proposed relationship mechanism.