The determination of the regional part of the vertical gradient anomaly by a geodetic method

Summary The significance of the vertical gradients of gravity is great in geophysics and also in geodesy. In geophysics the observed vertical gradients can give valuable information about mass distributions close to the surface of the earth and in geodesy they may be used in determining the shape of the equipotential surfaces. The observed vertical gradients are very sensitive to masses close to the surface of the earth and they change very rapidly. Therefore, they should not be used for purposes such as the reduction of the observed gravity to the sea level. The normal vertical gradients are not the best either for this purpose because they are much too uniform on the surface of the earth. The best values for practical purposes are probably the regional vertical gradients.This paper presents a method to determine the regional vertical gradient anomalies in large areas from geodetic observations which, added to the normal part, will give the regional vertical gradients.