A “processing density’to calculate marine Bouguer gravity free of topographic variations in case of unknown bottom density
J. Malzac and A. Rousseau
Journal name: Geophysical Prospecting
Issue: Vol 26, No 4, December 1978 pp. 853 - 867
Info: Article, PDF ( 927.67Kb )
In marine gravity interpretation, the density required for the Bouguer correction is not easily measured, and, therefore, one often uses either standard values or extrapolates density from a station or a profile to an entire survey. If the real density varies, this leads to inconsistencies. In this paper a method is proposed to eliminate as much as possible the gravimetrical effects of real density variations. The principle is to apply Nettleton's method to the whole space, but also to use a continuously variable density in the Bouguer gravity computation. It is possible to avoid affecting real gravity anomalies by using stations situated on suitable area elements the optimal size of which is determined by the program. The density that is obtained is called “processing density’ because it is not a real one, but rather the resultant of the densities affect on each station. Use of the method is demonstrated on an example from the southeastern part of Bay of Biscay.