Geodetski list, Vol. 48 (71) No. 3, 1994.
Preliminary communication
An Improved Method of Earth's Crust Masses Modelling
Mario Brkić
; INA-Naftaplin, Zagreb, Hrvatska
Abstract
The basic objective of physical geodesy is the determination of the Earth's shape and gravity field from various data measured on the Earth's surface and in outer space. The gravity field's source is the mass distribution within the Earth's surface. Source irregularities are being mapped onto irregularities of different effects, such as gravity anomalies, deflections of the vertical and geoid undulations. The topography and its compensation probably represent the main irregularities of the gravity field. Removal of the effects of these masses from measured data results in smoother residual field that ensures more accurate modelling of the Earth's gravity field. Therefore it was tried to achieve, on the basis of the available data, the best possible modelling of the Earth's crust masses, to be more specific, by means of including surface density distribution and base sediments' depths, for purposes of geodetic measurements' reductions. The improved modelling method was theoretically described, implemented in Forsberg's software and tested by calculation of different terrain effects in a chosen part of Republic Croatia. Differences in effects gained by this method and by the usual simple modelling significantly exceed today's measurements' precision of the characteristic physical quantities. This justifies not only this research, but also points to the necessity of further improvements considering other Earth's interior layers as well.
Keywords
Hrčak ID:
292199
URI
Publication date:
30.9.1994.
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