Trisna Ikhsan Ningati, Muhamad Ragil Setiawan, Rahmat Nawi Siregar, Alamta Singarimbun, Emi Prasetyawati Umar, Rofiqul Umam, Hirotaka Takahashi
The increasing demand for sustainable energy has intensified the search for viable geothermal resources, necessitating advanced geophysical methods for efficient exploration. In the Sekincau Timur, Becingut, located between Batubrak District and Bandar Negeri Suoh District, West Lampung Regency, Lampung Province, Indonesia, has geothermal potential. This potential can be utilized and developed as a renewable and sustainable energy source. However, before exploitation and exploration can take place, an initial analysis of the subsurface structure is required to determine the location of geothermal potential in the area, in other words, delineation. This study aims to determine the patterns of gravity anomalies, rock density contrasts, and subsurface structures of the Sekincau Timur geothermal field in Lampung Province, Indonesia. In this study, the subsurface structure will be modelled in 2D with secondary data from residual anomalies and regional topography experiment (TOPEX) anomalies. The results of the study indicate that the gravity anomaly patterns exhibit low variation with a rock density range of 1.00-2.55 g/cm3, moderate variation with a rock density range of 2.22-2.76 g/cm3, and high variation with a rock density range of 2.72-3.00 g/cm3. 2D modelling produced a subsurface structure in the form of a fault with a direction from the northwest to the southeast and from the northeast to the southwest, with topsoil at a depth of 0.00-0.11 km, caprock (cover rock) at a depth of 0.20 km, the reservoir is at a depth of 1.20-1.60 km, the recharge area (where meteoric water enters) is at a depth of 0.30 km, and a pull-apart basin is at a depth of 0.40 km. The results highlight the correlation between gravity anomalies and geothermal activity, offering insights into optimal drilling targets and long-term energy extraction feasibility. This analysis not only contributes to geophysical exploration methodologies but also reinforces the importance of integrating gravity data with multidisciplinary approaches for responsible geothermal development. © 2026 ICIC International
Department of Physics, Institut Teknologi Sumatera, Jalan Terusan Ryacudu, Jati Agung, South Lampung Regency, Lampung, 35365, Indonesia; Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10, East Java, Bandung, 40132, Indonesia; Department of Mining Engineering, Universitas Muslim Indonesia, Jalan Urip Sumoharjo 14, South Sulawesi, Makassar, 90231, Indonesia; Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Ibaraki, Tsukuba, 305-8577, Japan; Research Center for Space Science, Advanced Research Laboratories; Department of Design and Data Science, Tokyo City University, 3-3-1, Ushikubo-Nishi, Tsuzuki-Ku, Kanagawa, Yokohama, 224-8551, Japan