Changes in the earth’s rotational velocity and figure deformation associated with them

Abstract

© 2020, Kazan Federal University. All rights reserved. It is established that continuous changes of angular velocity of rotation of the plastically-elastic Earth should cause the continuous coupled deformation of a crustal layer, redistribution of masses in a sub-crustal layer and the change of density associated with it, and also, as a con-sequence of these phenomena, a polar pulsation of a figure when polar diameter of the Earth increases and decreases with time. The mechanism of occurrence of deformations of the planet body under action of a deforming (centrifugal) variable force is found; the tensors of deformations and pressure are written out; and, on the basis of the rheological equations, the equations of balance are deduced, and also calculation of the module of change of polar compression and radial displacements is made at real fluctuations of angular velocity of rotation of the Earth. The calculated values give 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: the observed fluctuations of amplitude of the polar compression, which lead to respective alterations of the moment of inertia of the Earth, quite correspond to real fluctuations of the day length.