Design and Implementation of Forward and Inverse Gravity Modeling Tool

Abstract

The implementation of a tool to perform two-dimensional forward and inverse gravity data modeling that can be used to interpret the subsurface geologic structure is presented in this article. The approach subdivides the subsurface into regular shape prisms and reconstructs the geologic  structures by assigning variable densities to the different prisms. To obtain the subsurface density distribution one will first use the forward modeling tool and generate a plausible model of the subsurface to use it later as the initial model in the inversion program. The inversion tool makes use of the compact gravity data inversion algorithm to iteratively model the subsurface. The advantage of this approach is that the desired geological characteristics are automatically incorporated into the model with a minimum subjective judgment on the part of the interpreter. The method was demonstrated by inversion of synthetic and real data. The synthetic data is generated from a two–dimensional model consisting of a regular array of identical blocks whose densities can be individually specified. While testing the application on real data that were collected around Filwoha (Addis Ababa), the resulting subsurface structural model produced gravity data that matched with the observed gravity data, within a predefined acceptable root mean square error.

Keywords: Gravity Anomaly; Forward Gravity Modeling; Inverse Gravity Modeling