Structural Control and Evaluation of the Geothermal System in Seulawah Agam, Aceh: A Geological and Geophysical Approach Using Fault Fracture Density, Land Surface Temperature, and Gravity Data

Abstract

Seulawah Agam, located in Aceh Province, is a Quaternary stratovolcano with notable geothermal manifestations, making it a promising target for renewable energy exploration. This study aims to evaluate the geothermal system and its structural controls through an integrated geological and geophysical approach. Geologically, Fault Fracture Density derived from remote sensing data is used to identify major fault zones, ridgelines, and structural trends that may act as conduits for geothermal fluid migration. Land Surface Temperature (LST) data from thermal infrared satellite imagery are employed to detect surface thermal anomalies indicative of subsurface geothermal activity. Geophysically, gravity data processed into Complete Bouguer Anomaly (CBA) and derivative maps are used to delineate subsurface structures, density contrasts, and potential heat sources. The study area covers approximately 17 × 16 km, with Bouguer anomaly values ranging from a minimum of 394.74 mGal to a maximum of 614.23 mGal. The integration of these datasets allows for the correlation between surface features and deeper geothermal reservoirs, highlighting structurally controlled zones with elevated geothermal potential. Preliminary findings indicate that NE-SW and NW-SE trending lineaments intersect with thermal anomalies and gravity lows, suggesting the presence of deep-seated fractures and fault zones associated with heat migration pathways. The study emphasizes the importance of structural mapping and geophysical validation in assessing geothermal viability. This integrated approach provides a robust foundation for future exploration efforts in Seulawah Agam and supports Indonesia’s broader goals for sustainable and renewable energy development in tectonically active regions.