ANALYSIS OF LEMBANG FAULT STRUCTURE BASED ON RESISTIVITY USING INVERSION 2-D MAGNETOTELLURIC METHOD

• Main Author: Nada, Qhathrin
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67346
• Institution: Institut Teknologi Bandung

An earthquake is a geological event due to tectonic or volcanic activity. Movements in the earth's crust cause earthquakes due to tectonic activity. One of the causes of tectonic activity is faults. The Lembang Fault is located 15 km north of the city of Bandung. The Lembang Fault is an active fault that has a normal fault type with a slip rate of 0.3 cm-1.4 cm per year. In this research, the magnetotelluric method was used to model the subsurface resistivity of Lembang fault. A profile consisting of nine measurement sites was taken perpendicular to the Lembang fault. The initial analysis of the Lembang fault was carried out through apparent resistivity data at three different frequencies, namely 115 Hz, 11.2 Hz, and 1.02 Hz, which showed a significant decrease in apparent resistivity in the area around the Lembang fault. Magnetotelluric modeling using Occam 2D inversion with finite difference method obtained a misfit value of 7.6 with 34 iterations. The inversion results show a resistivity contrast around the LMB02 site, which is suspected to be the Lembang fault. This result is in good agreement with the geological data in the Lembang fault area. In addition to the LMB02 site, there is also a resistivity contrast around the LMB05 site. However, geologically it is not known whether the area around the LMB05 point is a fault or other geological structure.