MODELING OF MAGNETIC DATA FOR IDENTIFICATION OF THE UNDER SURFACE STRUCTURE OF THE GEOTHERMAL PROSPECT AREAS (CASE STUDY IN REGION X)

• Main Author: Raintina, Yolanda
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49706
• Institution: Institut Teknologi Bandung

Indonesia is a country that has the largest geothermal content in the world at 40% of geothermal in the world. The supply of geothermal resources owned by Indonesia is beneficial for Indonesia itself because of the increase in population and the needs of the Indonesian population in the use of electricity. Geothermal is a renewable energy resource that needs to be developed by Indonesia to fulfill country's electrical energy needs. Therefore, further exploration is needed in observing geothermal sources. Geophysics is one of the application of physics that applies physics principles in solve problems related to earth. One of the geophysical method that simple to use is a magnetik method in which this method uses basic measurements based on the magnetik field on the surface of the earth because of the anomali of objects magnetized below the earth's surface. In this Final Project, magnetization will be analyzed on the earth's surface by knowing the composition of rocks in the subsurface structure. In general, rocks have relatively small terrain values and temperature affect their values. The higher the temperature, the object will demagnetize. To find out the subsurface structure of the earth, Mag2DC software can be used. This device uses a trial and error method to model the contrast value of magnetik susceptibility in rocks. If the susceptibility contrast is negative, then there is a magnetik anomali where there is a geothermal source. In the initial step of modeling, the selected area is an area that has a magnetik anomali with moderate to low magnetik susceptibility contrast. In the modeling obtained there is a magnetik susceptibility contrast which is negative and is at a depth close to the earth's core. This area indicates the existence of geothermal sources. As for obtaining the modeling of the structure of the surface of the earth below it is needed an analysis in the study area that the dominance of existing rocks to be able to accurately determine the rocks making up the underground surface structure. In the modeling, there are four types of rocks that make up the subsurface structure, namely tuff rock, tuff breccia, pyroclastic rock and weathered rock.