Aplication of Horizontal Gradient and Euler Deconvolution Methods for Gravity Data Analysis of Batur Volcano, Bali, Indonesia

Abstract

Mount Batur is an active volcano located at the center of two concentric calderas north-west of Mount Agung, Bali, Indonesia. The south east side of the larger 10×13 km caldera contains a caldera lake. Batur caldera formation on the geology consists of geologic rock formations containing Batur volcano agglomerates, lavas and tuffs. This area has been in the preliminary study phase of geology, geochemistry, and geophysics for geothermal exploration. As one of the geophysical study, the gravity of the area was surveyed in an attempt to delineate the subsurface structure and to better understand the relationship between the geothermal systems and the subsurface structure. The gravity bouguer anomaly data were analyzed using integrated gradient interpretation techniques, such as the Horizontal Gradient (HG) and Euler Deconvolution (ED) methods. These techniques detected boundaries of body anomalies and faults structure that were compared with the lithologies in the geology map. The analysis result will be useful in making a realistic subsurface mapping of Batur volcano, Bali.