DENTIFIKASI KAWASAN ZONA PANAS BUMI (GEOTHERMAL) DI DAERAH X MENGGUNAKAN METODE MAGNETOTELLURIK

Abstract

Geothermal is the heat formed inside the earth's crust. The heat of geothermalproduces hot water, steam, and heat rocks along with other minerals and gases to be genetically inseparable in geothermal systems.One of the geophysical method which can be used to determine the area ofa geothermal systemis magnettoteluric. The method is based on the valuesofresistivity distribution of the rock formation. In the study on the identification of geothermal zone in the X area, it was found the resistivity distribution in 1D and 2D modelsby using the magnettoteluric method.The models were created by processing of magnettoteluric data taken from three measuring lines. The 1D model was the resistivity distributionvertically generated from the depth of each measurement point, whilethe 2D model was the resistivity distribution generated in vertical and lateral to formthe image of geothermal system.Inthe 1D model the resistivitydistribution values were in the range of66ohm.m and 270 ohm.m, while in the 2D model the resistivity distribution values were in the range of 66 ohm.m and 221 ohm.m. From the image it could be interpretedthe low resistivity related to thecap rockzone located above the reservoir zone, the medium resistivity related tothe reservoirzonelocated below the cap rock zone, and the high resistivity related to the heat source zone located below the reservoir zone. The study found that the position of geothermal reservoir was under the cap rock zone.