MAGNETIC BASEMENT RELIEF MODELLING USING THE MAGB_INV PROGRAM IN SOUTH OF THE MAKASSAR STRAIT AREA

• Main Author: Alifna, Riyandra
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/73675
• Institution: Institut Teknologi Bandung

Indonesia is located between three large plate confluences: Indo-Australian, Eurasian, and Pacific. The activity of the three plates will affect the orientation and distribution of geological structures such as the formation of faults and basins. This research was conducted in the South of the Makassar Strait and covered two basins, namely the Makassar Basin and the Spermonde Basin, which are passed by the Makassar Basin Down Fault and the Spermonde Basin Horizontal Fault. The magnetic method is used in research to provide magnetic modeling information in the research area. This method works based on measuring variations in susceptibility on the surface of the earth caused by differences in anomalies in the surrounding area. The value of the natural magnetism of rocks can be used to map magnetic basement relief. The data used in this study are magnetic anomaly data obtained from the ESDM geoportal and bathymetry data from the study area. In this research, magnetic basement relief modeling was carried out using the MATLAB-based MagB_Inv program. This program is capable of processing large amounts of data quickly and with high accuracy by calculating the inverse Fourier transform. A high cut-filter is used in this program to avoid high-frequency instability. The initial parameters that affect the final results of the study are inclination and declination, magnetization contrast, selection of the wavenumber range, and initial depth estimation. The initial depth estimation was obtained using the Radially Average Power Spectrum (RAPS) method. The results of this study are basement depths in the range of 5.5 km to 8.9 km. In accordance with the geological conditions, it can be seen that there is a subsidence of the basement to the southeast in 3D modeling caused by the Spermonde Basin Fault.