UNDERSTANDING GEOELECTRICAL METHOD FOR DETECTING ELECTRICAL PROPERTIES BENEATH THE EARTH SURFACE

• Main Author: LUTFA (NIM: 90214003), ASNA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25861
• Institution: Institut Teknologi Bandung

Geoelectrical method is one of geophysical method for detecting electrical properties beneath the earth surface. Before using geoelectrical method in the real world experiment, the method should be understood correctly to obtain the good results. Therefore, a project in laboratory scale was made to give understanding the geoelectrical method. Geoelectrical method was applied by injecting electric current on medium surface through two current electrodes, then measuring potential difference between two potential electrodes that appeared on medium <br /> <br /> surface. The research was be done by applying geoelectrical method on miniature of earth modeling. The structure of miniature consisted of three medium layers, <br /> <br /> they were sandy soil, black sand, and clays. The miniature was made on a container with a length of 200 cm, a width of 80 cm, and a height of 80 cm. The structure of medium was composed in varying layers, these were: (1) clays, sandy soil, black sand; (2) sandy soil, clays, black sand; (3) sandy soil, black sand, clays; and (4) black sand, sandy soil, clays. In this paper, schlumberger configuration was used. The results of measurement was apparent resistivity. In order to determine true resistivity, inversion technique was done using IP2Win software. <br /> <br /> This research has shown that geoelectrical method is capable to detect variation of resistivity beneath the earth surface, resistivity of clays is 26,2-45,5 &#937;m, <br /> <br /> resistivity of sandy soil is 335-634 &#937;m, while resistivity of black sand is 450-6603 &#937;m. When electrical current injected into medium, the depth reached by electric current depends on reflection coefficient possibly. In the medium has many layers, the electric curent flow will be distorted toward the normal at a plane interface when passing from the medium with low resistivity to the medium <br /> <br /> underneath with high resistivity, vice versa.