Dvulit P. Methods of accounting the geophysical factors influences on Earths gravitational field variations.

The dissertation is devoted to the problems of accounting the geophysikal factors influences on variations, of the Earths gravitational field. Influences are considered caused by anomalous atmospheric masses, snow cover masses, variations of underground waters level, wooded, redistribution of masses in Earths interior, technogeneous factors. The theory is developed and basic formulae are derived for accounting these geophysical causes in gravity, level surface deformations, second order derivatives of gravity potential and plumb line deflections. Various methods are proposed for the cases when a digital model for geophysical fields parameters is known at arbitrary cuscrete points on the Earths surface, ata cartographic grid or by a spherical harmonic exspansion. It was shown that influences of geophysical factors must be accounted for interpretations of repeated absolute gravity measurements, for analyses of repeated levellings and for evaluations of changes in astronomical latitudes and zenith at obs ervatories. Main results of the theoretical and experimental studies were used in a number of geophysical and geodetic institutions which deal with study of the Earths gravity field instability. Keywords: atmospheric masses, snow cover, underground waters level, wooded, gravity potential, gravity acceleration, level surface, plumb line deflections. Interpolation, approximation.