ESTIMATION OF CURIE POINT DEPTH USING SPECTRAL ANALYSIS TO DETERMINE GEOTHERMAL GRADIENT VALUES AND HEAT FLOW IN MAGNETIC DATA IN THE CENTRAL JAVA REGION

• Main Author: Raihan Ulil Albab, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/75226
• Institution: Institut Teknologi Bandung

Geothermal is one of the alternative energies to fulfill energy needs. Indonesia is a country that has great potential to develop geothermal energy. One of the geophysical methods that can be used is the magnetic method which is based on differences in the magnetic properties of rocks. Geothermal areas will have a lower rock magnetic intensity than their surroundings because an increase in temperature will result in a reduction in the magnetic properties of rocks. Through the magnetic method, we can find out about the heat system under the earth's surface by determining the depth of the Curie point, as well as the geothermal gradient and heat flow. This research will use aeromagnetic data in the Central Java region taken from the Magnetic Anomaly Map of East and Southeast Asia to determine the depth of the Curie point and geothermal gradient and heat flow using magnetic data to find out information on subsurface heat systems. The study area has an area of 345 × 198 ????????2 which is divided into 85 blocks. Each block has an area of 40 × 40 ????????2 using an overlap between blocks of 50% and 2D spectral analysis is carried out to estimate the depth of the top (????????) and the depth of the centroid (????0) which results in the Curie point depth value of each block. The result of Curie point depth in the study area is about 8 to 20 km. Shallow Curie point depths are found in areas where there are volcanoes and hot spring manifestations while deep Curie point depths are found outside these areas. Curie point depth values are used in calculations to find geothermal gradients and heat flow. The study area has a geothermal gradient ranging from 27 to 67 °????/???????? and heat flow has a value range of 69 to 167 mW/????2. Geothermal gradient values and high heat flow found in areas where there are volcanoes and hot water manifestations while outside the area found geothermal gradient and low heat flow. Areas that have low Curie point depth values, geothermal gradients and high heat flow can potentially develop geothermal energy