Abstract
The compilation of new global Mohorovičić (‘Moho’) topographic data enables the density contrast between the crust and mantle to be estimated. Assuming that this contrast is constant, the minimization of the external gravitational potential induced by the Earth's topographic masses and the Moho discontinuity yields the value of 0.28 g/cm3 for the density jump at the Moho. Moreover, it is shown that the Airy Heiskanen model of compensation only partly compensates the surface topographic masses. To fit the external gravitational potential, induced by the surface topography, the Pratt-Hayford concept of compensation has to be considered. Employing the dynamical flattening of the Earth, the minimum depth of compensation has been estimated at 100–150 km. This means that the topographic masses are compensated throughout the Earth's lithosphere at least.
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References
Čadek, O. and Martinec, Z.: 1991, ‘Spherical Harmonic Expansion of the Earth's Crustal Thickness up to Degree and Order 30’,Studia Geoph. et Geod. 35, 151–165.
Dziewonski, A. M. and Anderson, D. L.: 1981, ‘Preliminary Reference Earth Model’,Phys. Earth Planet Inter. 25, 297–356.
Heiskanen, W. A. and Moritz, H.: 1967,Physical Geodesy, Freeman and Co., San Francisco.
Kopal, Z.: 1960,Figures of Equilibrium of Celestial Bodies, Univ. of Wisconsin, WI, pp. 135.
Marsh, J. G., Lerch, F. J., Putney, B. H., Christodoulidis, D. C., Felsentreger, T. L., Sanchez, B. V., Smith, D. E., Klosko, S. M., Martin, T. V., Pavlis, E. C., Robbins, J. W., Williamson, R. G. Colombo, O. L., Chandler, N. L., Rachlin, K. E., Patel, G. B., Bhati, S. and Chinn, D. S.: 1988, ‘An Improved Model of the Earth's Gravitational Field: *GEM-T1*’, NASA Techn. Memorandum4019, pp. 354.
Martinec, Z.: 1991, ‘On the Accuracy of the Method of Condensation of the Earth's Topography’,Manuscr. Geod. 16, 288–294.
Martinec, Z.: 1992a, ‘The Density Contrast at the Mohorovičiè Discontinuity’,Geoph. J. Int., in print.
Martinec, Z.: 1992b, ‘The Minimum Depth of Compensation of Topographic Masses’,Geoph. J. Int., in print.
Moritz, H. and Mueller, I. I.: 1987,Earth Rotation. The Theory and Obsevation, Ungar Publ. Co., New York.
Nakiboglu, S. M.: 1982, ‘Hydrostatic Theory of the Earth and its Mechanical Implications’,Phys. Earth Planet. Inter. 28, 302–311.
Pěč, K. and Martinec, Z.: 1984, ‘Constraints to the Three Dimensional Non-Hydrostatic Density Distribution in the Earth’,Studia Geoph. et Geod. 29, 364–380.
Rummel, R., Rapp, R. H., Sünkel, H. and Tscherning, C. C.: 1988, ‘Comparisons of Global Topographic/Isostatic Models to the Earth's Observed Gravity Field’, Dept of Geodetic Science and Surveying, Rep.388, The Ohio State University, Columbus.
Sansò, F., Barzaghi, R. and Tscherning, C. C.: 1986, ‘Choice of Norm for the Density Distribution of the Earth’,Geophys. J. R. Astr. Soc. 87, 123–141.
Tarantola, A. and Valette, B.: 1982, ‘Generalized Nonlinear Inverse Problems Solved Using the Least Squares Criterion’,Rev. Geoph. Space Phys. 20, 219–232.
Tscherning, C. C. and Sünkel, H.: 1981, ‘A Method for the Construction of Spheroidal Mass Distributions Consistent with the Harmonic Part of the Earth's Gravity Field’,Manuscr. Geod. 6, 131–156.
Wieser, M.: 1987, ‘The Global Digital Terrain Model TUG89’,Inter. Report on Set-up, Origin and Characteristics, Inst. of Math. Geodesy, Technical Univ. of Graz, Austria.
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Martinec, Z. A model of compensation of topographic masses. Surv Geophys 14, 525–535 (1993). https://doi.org/10.1007/BF00690575
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DOI: https://doi.org/10.1007/BF00690575