Land gravity data acquired over part of North Sumatera Basin, Indonesia, was used to estimate depth to multiple horizons of density interface. Recently, gravitational data has difficulty to map the depth of subsurface layer structure except by using modeling. Here, we apply the energy spectral analysis-multi window test (ESA-MWT) technique to map the subsurface horizons. The estimated depth was computed from energy spectral analysis as the transformation of the gridded gravity data to 2D Fourier transform (Fast Fourier Transform). The energy spectrum analysis is performed at a test point by windowing the gridded complete Bouguer anomaly (CBA) at that test point with the square window size constantly increasing 1 km width from the previous window size. The distance between the test points is about 2 km on each of the gravity measurement lines. Plateau depths are then obtained which represents the density interfaces of the plot result between the depths of the anomaly to the window size. The results of the mapping of density interfaces correspond to sedimentary interfaces, those are the economic basement as Top Tampur Formation (Horizon 1), the top of several other sedimentary interfaces (Horizon 2-6), one of them is Top Belumai Formation (Horizon 2).
|Journal||IOP Conference Series: Materials Science and Engineering|
|Publication status||Published - 1 Jul 2020|
|Event||2nd International Conference on Science and Innovated Engineering, i-COSINE 2019 - Malacca, Malaysia|
Duration: 9 Nov 2019 → 10 Nov 2019