Abstract
The Terrain Correction Table was intended for use primarily on a routine gravity survey for oil exploration where structure of interest will be a minimum of several hundred ft deep and the time involved in making the determination is of importance. Nevertheless, the table is equally adaptable to closely-spaced stations if proper care is exercised in determining the elevation differences in the various compartments. For corrections larger than 0.01 mgal, the table has been graduated in steps of 0.01 mgal, which is the limit of accuracy of most gravimeters; however, where greater accuracy is required, closer terrain determinations can be made by interpolation. The near-surface density must be taken into consideration in using the table as a density of 2.0 was selected for the base. The near-surface density effect is of more concern in the Bouguer rather than in the terrain correction since the latter is the smaller of the two, approaching insignificance, especially in Zones B and C, if proper care is exercised in selecting the observation site.
