The density difference and generalized programs for two-and three-dimensional gravity modeling

Abstract

Computer programs developed to model flat-topped bodies cannot accommodate models with a flat bottom, without a modification in the program. The concept of density difference is introduced and used to construct computer programs that can model gravity anomalies of any body—flat topped, flat bottomed, or undulating. The density difference is the density of the material lying below the interface minus the density of the material above. The suggested schemes determine the initial depths to the interface based on the Bouguer slab formula and improve them iteratively based on the differences between the observed and calculated anomalies. Two generalized computer programs in FORTRAN 77 for modeling two- and three-dimensional structures are presented.