Mayang Bunga Puspita, Sukir Maryanto, Naufal Helmi Ramadhani
The current focus of energy development in Indonesia is on renewable energy, and one of these sources is geothermal energy. Pacitan is an area in Indonesia with the potential for geothermal energy, as evidenced by the presence of Karangrejo and Tinatar manifestations as hot springs. Limited geophysical research has been conducted in this particular area. This research aims to identify geological structures by analyzing geomagnetic anomalies. The geomagnetic method is chosen because it can detect demagnetization zones, which indicate heat flows from geothermal systems, as well as analyzing geological structure by geomagnetic anomalies. The study utilized 144 data points within a 5×5 km2 area, collected on August 2nd–8th, 2022. The data was processed by diurnal variation correction, main field corrections, Reduction to Pole (RTP) filter, and regional-residual anomalies separation. The results revealed a range of residual anomaly magnetic field values from -150.3 nT to 140.8 nT in the research area. The high anomalies are correlated with volcanic breccia, lava, and tuff. Meanwhile, the low anomalies are correlated with fluvial deposits. Faults were identified by residual anomalies, suggesting a possible connection to the local Karangrejo and Tinatar faults and the presence of the Grinjing Fault. This research concluded that these faults allow hot fluid to manifest on the surface. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.
Geophysical Engineering Sub-Department, Brawijaya University, Malang, Indonesia; Student of Geophysical Engineering Sub-Department, Brawijaya University, Malang, Indonesia
