SUBSURFACE MODELING OF SINABUNG VOLCANO AREA BASED ON GRAVITY DATA ANALYSIS

• Main Author: Pertiwi, Dita
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42090
• Institution: Institut Teknologi Bandung

Indonesia is a country that has many volcanoes because of its geological location at the confluence of three tectonic plates, Indo-Australian, Eurasian, and Pacific plate. Interaction between the three plates take part in volcanic formation in Indonesia, one of them is Sinabung volcano. Sinabung volcano is located in Karo, North Sumatra with an altitude of 2.460 meters above sea level. Since 1600, Sinabung has not shown volcanic activities so it was classified as a type B volcano. However, in 2010, Sinabung erupted with a large eruption and still shows volcanic activities until now. So, this study was conducted to determine the subsurface structure of Sinabung Volcano in hope that can be used as material for further research in geological hazard mitigation. In this study, 2,5 dimensional modeling was done by using gravity method. Gravity method is a geophysical method based on measurements of gravitational field variations on the surface. The data used in this study was a complete Bouguer anomaly map that digitized with Surfer to produce a digital complete Bouguer anomaly map. After that, regional and residual anomalies were separated by moving average method. For modeling, ModelVision 13.0 was used with residual anomalies and topograph as input data. Based on the reference, background density was 2,67 g/cc. The model was made by estimating subsurface geological conditions in the study area using geological, geophysical, and other literature information. The depth of magma chamber could not be modeled with residual anomalies as input data. Because, based on spectral analysis, estimated average depth of residual anomalies was shallow about 3.000 meter