A SUITABLE PROCESS FOR REGIONAL-RESIDUAL SEPARATION OF GRAVITY FIELD

Observed Bouguer gravity anomalies contains superposed anomalies from different sources expressed by long-wavelength related to deep and large scale structures of the Earth crust called regional, and short- wavelength anomalies related to near surface anomalous masses called residual. The separation of regional and residual is an important step in the gravity data analysis. In case of lack of information on geologic deep structures of the studied area, the decomposition of the observed gravity anomaly into regional and residual becomes very delicate and numerous techniques ranging from simple visual inspection to advanced mathematical analysis could be used. In this study we present a regional-residual separation flow- chart procedure based on the integration of least-squares polynomial, power density spectrum and upward continuation techniques. The proposed procedure allows to obtain a suitable decomposition and avoid an arbitrary choice of regional anomaly. The proposed process is checked on synthetic data then it’s applied to real gravity data.