3. The components of the deflection of the vertical [xi] and
[eta] at any point, oceans and islands included.
4. The conversion of existing geodetic systems to the same world
geodetic system.
5. The reduction of triangulation base lines from the geoid to
the reference ellipsoid.
6. The correction of errors in triangulation in mountainous
regions due to the effect of the deflections of the vertical.
7. Geophysical applications of gravity measurements, e.g., the
isostatic study of the earth's interior and the exploration of
oil fields and ore deposits.
With astronomical observations or with existing triangulations, the
gravimetric method can accomplish further results. Heiskanen and Vening
Meinesz state:
It is the firm conviction of the authors that the gravimetric
method is by far the best of the existing methods for solving
the main problems of geodesy, i.e., to determine the shape of
the geoid on the continents as well as at sea and to convert the
existing geodetic systems to the world geodetic system. It can
also give invaluable help in the computation of the reference
ellipsoid.[114]