THE ANALYSIS OF SUBSURFACE STRUCTURES IN PAPANDAYAN VOLCANO CRATER AREA BASED ON GRAVITY METHOD (2018)

• Main Author: Rizqa Pradani, Adinda
• Format: Final Project
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/38078
• Institution: Institut Teknologi Bandung

Indonesia is a country located in the Pacific Ring Of Fire, one of the volcanic belts in the world. Therefore, volcano disaster mitigation efforts need to be done through research and survey to minimize the impact of volcanic disasters. The survey aims to determine the subsurface geological structure of the volcanic crater region with various methods, one of them is geophysical method. In this research, volcano that will be studied is the Papandayan Volcano using the gravity method. The gravity method is a geophysical method used to measure variations in the value of the gravitational acceleration of an area due to variations in the distribution of rock density below the surface. In this study, LaCoste & Romberg G-928 gravimeter was used. By using the parasnis method, a density value of 2,45 g/cm3 is obtained. Separation of complete bouguer anomaly into 2 types of regional and residual anomaly using the first order of polynomial fitting methods. Based on the residual anomaly map, an incision path was determined in the area which predicted to have anomalies. From the 2D modeling results were obtained 3 layers of constituent rock below the surface, namely the first layer in the form of pyroclastic rocks and andesite rocks which have the same density as the average density of surface rocks with density ranges from 2,45-2,81 gr/cm3. In the second layer there is clay with density ranges from 2,25-2,5 gr/cm3. While the third layer which is located in the deepest, is predicted to be basalt rocks with density value is 3,26 gr/cm3.