ONE DIMENSIONAL CONTROLLED-SOURCE AUDIO-FREQUENCY MAGNETOTELLURICS (CSAMT) DATA INVERSION MODELING USING OCCAM METHODS

• Main Author: Budhi Satrio Utomo, Leonardo
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65778
• Institution: Institut Teknologi Bandung

The Controlled-Source Audio-Frequency Magnetotellurics method is an active geophysical method that utilizes the physical properties of EM waves to measure rock resistivity values beneath the surface. Generally, CSAMT is used for geothermal, mining, or oil and gas exploration. In its use, CSAMT data needs to be further processed with forward modeling or inversion modeling in order to be able to image the actual subsurface conditions. This research was conducted to test the accuracy of the development of the Levenberg-Marquardt inversion method into a simple Occam method in performing the inversion process of CSAMT data. This inversion modeling applies the basic properties of the Occam inversion method by looking for a smooth model that can be described in detail the original conditions of the subsurface profile. In this study, the modeling version tested on synthetic data refers to 4 types of sounding curve conditions, namely types A, H, K, and Q. The synthetic data used in this research has accommodated the actual conditions of the field data with the addition of a 5% noise parameter. on the impedance value generated from the forward modeling. The results of the inversion modeling test using the Occam approach are considered good, achieving optimal results with an ERMS value of less than 5%.