Gravity Anomaly Enhancement for Geothermal Prospect Characterization: A Comparative Application of First Horizontal Derivative, Second Vertical Derivative, and Regional–Residual Separation Using Surfer and Oasis Montaj
DOI:
https://doi.org/10.59890/ijsas.v4i10.86Keywords:
Gravity Anomaly, Comple Bouguer Anomaly, First Horizontal Derivative, Second Vertical Derivative, Regional–Residual SeparationAbstract
Gravity surveys help delineate structures controlling geothermal systems, but the Complete Bouguer Anomaly (CBA) mixes regional trends, residual signals, and noise. This study applies an anomaly enhancement workflow to CBA data (145–155.5 mGal) from a geothermal prospect of about 1.1 × 1.0 km and compares Surfer and Oasis montaj. After kriging and shaded-relief rendering, First Horizontal Derivative and Second Vertical Derivative filters were computed. Radial spectrum analysis yielded cut-off wavenumbers of 1.90 cycles/km (λ ≈ 525 m) and 7.54 cycles/km (λ ≈ 133 m) separating regional, residual, and noise components. The platforms differed in shading, SVD implementation, and separation domains; only Surfer supported spatial-domain separation. The workflow offers practical guidance for software selection in geothermal gravity exploration.
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