On the strained state tectonosphere Earth

: pp. 45 – 56
Received: October 05, 2016
Engineering geodesy department of Lviv Polytechnic National University
Engineering geodesy department of Lviv Polytechnic National University
Engineering geodesy department of Lviv Polytechnic National University

Purpose. Planetary problems related to the study of the stress state of Earth tectonosphere became of wide importance in geosciences. The purpose of this paper is show how gravitational-rotational forces cause density redistribution resulting in stress state of tectonosphere and consequently Earth shape and surface transformation during Earth self-evolutionary process. Also it is possible to determine acting forces, that cause the dynamic of the Earth stress state by solving the inverse problem using parameters of evolutionary changes of the lithosphere shape and surface. Methods. Previous studies reveal that the figure of the Earth lithosphere surface is slightly rotated relatively to the geoid figure. Such mutual arrangement of lithosphere surface and geoid result in stress aimed to the density redistribution within the Earth for being in accordance with geoid surface. The solution to this problem is considered based on approximation of the Earth lithosphere by two-axial ellipsoid. Such approach was used for approximation of DTM ETOPO1. For estimating of ellipsoid parameters (smilaxes, shifts, rotations) topographical heights of ETOPO1 model were averaged in the 5º×5º trapezoids. Introducing the notion of “geoevolutionary” a plumb line deviation and assuming that tangential stress forces are proportional to the angle  in between directions of plumb lines in the past geological era and nowadays direction at the set point it is possible to estimate acting stress forces in the upper shell of planet. Results. Algorithm for estimation of tangential forces and its interpretations from the point of view of Earth shape planetary dynamics investigations and global stressed state are proposed. The scientific novelty. The concept of “geoevolutionary” plumb line deviation is introduced and is used for computations of tangential forces acting on the top shell of the planet. Interpretation of the role of gravitational and rotation forces in formation of the global stress field in the Earth tectonosphere is given. The practical significance. The results are going to be used in further investigations aimed to the study of planetary characteristics its dynamical variations and global stress state of our planet.

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