Evaluation of bouguer gravity anomalies using global geopotential models: comparison with terrestrial data

Abstract

The Earth's gravitational field is a key physical parameter in geodesy, geophysics, and geodynamics, as it enables the study of the Earth's crust and its internal structure. Spatial variations in gravity are used to identify geological structures, determine the geoid, and establish vertical reference systems. In this context, the Bouguer anomaly is significant because it removes the effects of topography and surface masses, isolating contributions from deeper lithospheric structures. Modern gravimetric analyses increasingly rely on global geopotential models, which are mathematical approximations of the gravitational field derived from satellite missions, terrestrial measurements, and digital terrain models. In this study, terrestrial gravimetric measurements were compared with values of gravitational acceleration and Bouguer anomalies derived from the global geopotential models EIGEN-6C4 (European Improved Gravity model of the Earth by New techniques 6C4), XGM2019e (combined global Earth gravity field model 2019e), and EGM2008 (Earth Gravitational Model 2008). The analysis compares modeled Bouguer anomalies with data from a detailed gravimetric survey of the test area. Based on statistical parameters and the spatial distribution of anomalies, the quality of the evaluated models and their suitability for regional gravimetric studies were assessed