THE SIMPLE HEAT SOURCE MODELING OF KARAHA-TELAGA BODAS GEOTHERMAL SYSTEM USING GRAVITY METHOD

• Main Author: Ananto Putera Wisana, Epy
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46428
• Institution: Institut Teknologi Bandung

Along with the developing of technologies, the need of energy is also increasing. Fossil energy is estimated can not fulfill the world’s energy need in the near future. Clean and renewable energy is rising as the solution of this problem, which one of it is geothermal energy. Indonesia is an archipelago which located between three earth’s major tectonic plates, which are Eurasia, Indo-Australia, and Pacific plates. The interaction of those three plates actively contributed to the formation of the volcanoes in Indonesia. The number of volcanoes located in Indonesia makes it one of biggest country in term of geothermal energy exploitation potential. Gravity method is one of the geophysical methods which is used in the geothermal exploration. Basically, the gravity method is the measuring of gravity field variation which is caused by subsurface lateral density variation in result of the variation of rocks and minerals composition. In the end, gravity method is used to modelling the subsurface of a geothermal system. The data used for this research is the Complete Bouguer Anomaly (CBA) map of Karaha-Telaga Bodas geothermal system from a 1997 survey. The map is the used to make a digital CBA map. The next step is regional and residual anomaly separation, so that the residual anomaly map can be used for the 2.5D forward modelling process. Forward modelling is made based on the geological information so that the output can represent the actual condition as close as possible (background density = 2.5 g/cc). Based on the forward modelling result from the North-South oriented cross section, a separate granodiorite intrusion body under Karaha and Telaga Bodas is detected with density of 2.7 g/cc.