A microcomputer program for Tsuboi's method of gravimetic interpretation

Nowadays gravimetric data are extensively interpreted by approximating the subsurface situation with simple polygonal structures. Algorithms to calculate the effect of such structures have been presented for bodies striking at right angles to profiles under interpretation and having effectively infinite strike lengths, (Talwani, Worzei and Landisman 1959). Such methods have been termed 2-D. A slight modification of the method was used to interpret three-dimensional bodies (Talwani and Ewing 1960). Methods have also been proposed in order to overcome the disadvantage of the infinite strike length in 2-D interpretation. Such techniques, supposing finite strike lengths, are termed 2 1/2-D interpretational methods (Cady 1980). The microcomputer program presented in this work is based on the method proposed by Tsuboi, Tomoda and Aki (Tomoda and Aki 1955; Tsuboi 1983). It is a 2-D method for determining directly from gravity data the depth to a single density interface. It consists of calculating the deviation of the interface from mean depth by means of excess mass under each point on a profile where the gravity anomaly has been measured.