Performance of the finite element method for regional – residual separation on gravity method

Ilknur Kaftan*, Mujgan Şalk, Coşkun Sarı

Dokuz Eylul University, Faculty of Engineering, Department of Geophysics, 35160, Buca-Izmir, TURKEY


(Received 14 May 2010; Accepted 20 August 2010)

Abstract:  Separation of regional and residual anomalies in potential field applications has been studied considerably for years. Computing regional anomaly is a critical step in modeling and inversion in the gravity method. A number of techniques, both in space and frequency domains, have been developed for regional-residual resolution. Finite element approach is relatively a recent and new technique to compute the regional component. In this paper, data processing techniques, such as trend analysis, filtering, and finite element method were applied on synthetic and field gravity data to separate regional and residual gravity anomalies. In the synthetic applications,three structurally different models were used. Model I consists of three blocks having different volumes, geometrical shapes and density contrasts. Model II and Model III consist of two and three cubic blocks, respectively, having different volume and the same density contrast. In the real data application, the field gravity data were observed on the well-known Aswaraopet Fault (India). Basement depth of the Chintalpudi basin deduced from borehole information is approximately 3 km. The obtained results for all applications were compared with the ones from conventional data analysis methods such as the filtering and trend analysis. As a result, the Finite Elements Method is more preferable with respect to the conventional ones.