Pemodelan inversi data anomali gravitasi satelit untuk mengestimasi keberadaan dapur magma komplek gunungapi Sindoro-Sumbing, Jawa Tengah, Indonesia

Abstrak

Three-dimensional inversion modeling has been carried out to model the geological structure of the magma chamber in the Sindoro and Sumbing Volcanic complexes. The data used is high-resolution satellite gravity anomaly data from the Global Gravity Model Plus (GGMplus) in the research area with an area of 423.81 km². The results of accessing GGMplus data are gravity disturbance data with a value range of 69.44 – 299.01 mGal. Data has been processed by applying Bouguer correction to obtain Simple Bouguer Anomaly (SBA) data and terrain correction to obtain Complete Bouguer Anomaly (CBA) data. Next, data reduction was carried out on a horizontal surface using the Taylor Series approximation, and then regional and residual anomaly data was separated using the upward continuation method. Separation of the anomaly data produces residual data with values ranging from -74.96 – 29.05 mGal. The results of 3D inversion modeling on residual anomaly data show a low anomaly block with density values ranging from 1.50 ~ 1.59 g/cm³, located at a geographical position of 109.989° E and -7.304° S with a depth of around 1 - 5 km, interpreted as the magma chamber of Sindoro Volcano. The modeling results also show a low anomaly block at a geographic position of 110.071° E and -7.385° S with a depth ranging from 1 – 6 km, interpreted as the magma chamber of Sumbing Volcano.