Gravity inversion of closed two-dimensional bodies

An inversion scheme to trace the boundary of a closed two-dimensional body from its gravity anomalies is suggested. The body is replaced by a series of juxtaposing prisms. The initial values of the depths to top and bottom of these prisms are calculated and improved iteratively, using the method of ridge regression, until the anomalies of the model best fit the gravity anomalies. The input to the computer consists of the gravity anomalies, the density contrast, and approximate mean depth of the body and the horizontal boundaries of the body. The method differs from schemes using the polygonal cross-sections, in that the initial values of the parameters defining the cross-section of the body need not be supplied to the computer as the input.