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A Mechanism of Variations of the Earth Rotation at Different Timescales

Published online by Cambridge University Press:  12 April 2016

Yu. V. Barkin*
Affiliation:
Sternberg Astronomical Institute, Moscow, Russia

Abstract

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To explain the observed effects in the Earth’s polar motion, a mechanism of the relative motion of the lower mantle and upper mantle with a boundary at 670 km of depth is proposed. According to the new approach, the Earth’s layers (including separate plates) are considered as nonspherical, heterogeneous celestial bodies, interacting with each other, with the Moon and the Sun and executing a wide spectrum of relative motions in different timescales. The small displacements of the centers of masses of the lower and upper mantles and their relative rotations have here a primary importance. These displacements display themselves at various time scales (from a few months to millions of years), and their manifestations are readily detected in the regularities of the distribution of geological structures as well as in many geodynamical processes. Important regularities of the ordered positions of the plate centers, of their triple junctions, hot spots, systems of fractures and cracks, geographic structures, fields of fossils, etc., are observed as consequences of certain displacements and inclined rotations (Barkin, 1999). At geological time intervals, the slow motion of the layers causes mutually correlated variations of the processes of rifting, spreading, subduction, regressions and transgressions of the sea, of the plate motion, formation and breakdown of super continents, etc. The motions and the accompanying tectonic mass redistribution cause variations of the components of the Earth’s inertia tensor and geopotential, which lead to variations of its diurnal rotation and polar motion. Explanation of the main properties of the perturbed Chandler polar motion has been done.

Type
Part 4. Long-term Polar Motion
Copyright
Copyright © Astronomical Society of the Pacific 2000

References

Avsjuk, Yu. N., 1996, Tidal Forces and Natural Processes. RAN, M..Google Scholar
Barkin, Yu.V. 1996, Dynamics of the Earth’s Inner Core. Proceedings of the Sternberg Astronomical Institute. MSU. Moscow. 1996, pp. 107129. In Russian.Google Scholar
Barkin, Yu. V., 1999, Global Properties of the Structure, Evolution and Interactions of the Lithosphere and other Covers of the Earth. Proceedings All-Russian Conference “Interaction in the System of the Lithosphere, Hydrosphere and Atmosphere.” (Mosków, November 28-30, 1996). V.2, MSU. Moscow, pp. 4660. In Russian.Google Scholar
Barkin, Yu. V. Astronomical and Astrophysical transactions (in press).Google Scholar
Ferrándiz, J. M. & Barkin, Yu. V., 2000 Nature and Properties of the Chandler Motion and Mechanism of its Damping and Excitation. This proceedings.Google Scholar
Kinoshita, H., 1977, Celestial Mechanics, 15, 277326.Google Scholar
Vondrák, J. & Ron, C. 1996In: Capitaine, N., Kołaczek, B., Débarbat, S., Journées 1995 Système de Référence Spatio-temporels, Space Research Centre Warsaw, 95102.Google Scholar