Integrated satellite gravity analysis and HVSR microtremor measures for geothermal potential assessment in the Suban Curup–Rejang Lebong Hot Spring Area, Indonesia

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

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.

Structural and thermal analysis of geothermal prospectivity in the Midyan Basin, NEOM, Saudi Arabia

The Midyan Basin in the NEOM region of northwestern Saudi Arabia is a promising yet underexplored geothermal province situated within the tectonically active Red Sea Rift and Gulf of Aqaba transform system. Despite evidence of elevated regional heat flow and shallow Curie depths, the structural controls governing geothermal fluid circulation remain poorly constrained. This study identifies structurally controlled geothermal targets by integrating remote sensing, airborne geophysics, and field observations within a unified exploration framework. Multi-temporal Landsat-8 imagery acquired during six months of the year 2024 was used to derive land surface temperature (LST) through radiance-to-brightness temperature conversion and NDVI-based emissivity correction. Surface structural lineaments were interpreted from multidirectional hillshade models derived from a 30-m digital elevation model (DEM), while subsurface fault systems were delineated from airborne magnetic data using tilt-derivative analysis. Fault fracture density (FFD) mapping identified structurally enhanced permeability zones, which were integrated with persistent LST anomalies to delineate geothermal prospectivity. The analysis identified 5,809 surface lineaments and 1,262 basement-rooted magnetic lineaments, both dominated by NW–SE and NE–SW structural trends associated with the Red Sea Rift and Gulf of Aqaba transform system. Geothermal prospectivity is concentrated within discrete basement-rooted fault corridors rather than being uniformly distributed across the basin. The highest-confidence targets occur along the western and northwestern coastal escarpments, where high surface and subsurface fracture densities spatially coincide with persistent multi-season thermal anomalies, indicating enhanced permeability and structurally controlled heat transfer. Three priority geothermal target zones (Surface Zones A, B, and C and corresponding Subsurface Zones A′, B′, and C′) were identified, with Zone B/B′ representing the most prospective area owing to its strong structural continuity across surface and subsurface datasets. Field observations of dense fracture networks, fault-controlled granite–carbonate contacts, and subvertical dike swarms further corroborate the interpreted permeability pathways. Although direct geothermal manifestations and drilling data are not yet available, the integrated structural, thermal, and field evidence demonstrates that the Midyan Basin possesses favorable geological conditions for both hydrothermal resources and Enhanced Geothermal Systems (EGS). The proposed workflow provides a robust, cost-effective screening approach for reducing exploration uncertainty and prioritizing geothermal targets. It also guides future geothermal exploration and development within NEOM.

Geomorphic and Remote Sensing‐Based Evaluation of Active Faults and Geological Hazards in the Muzaffarabad Region, NW Himalaya

Geomorphic features, drainage patterns and topography are key indicators of active tectonics. This study examines geomorphological characteristics and geological hazards, specifically earthquakes and landslides, in the Muzaffarabad region. The findings contribute to disaster risk reduction and achievement of sustainable development goals (SDGs). Field‐based geomorphological studies and satellite imagery were used to analyse the geomorphological characteristics of the region. Five geomorphic indices, namely asymmetry factor (AF), drainage basin shape index (Db), slope analysis, valley floor width‐to‐height ( V f ) ratios and hypsometric curves, were calculated using shuttle radar topography mission digital elevation model (SRTM DEM). Features such as drainage offsets, stream deflections, faceted spurs, seismicity, deformed recent sediments and point bars dissection near the Jhelum and Muzaffarabad faults suggest left‐lateral oblique‐slip motion, indicating the tectonically active nature of these faults. The geomorphic and neotectonics analysis concludes that the Muzaffarabad region is highly susceptible to earthquakes and landslides, particularly, in fault‐affected areas. A flood susceptibility analysis using multi‐criteria decision analysis (MCDA) in ArcGIS was conducted to enhance climate resilience and disaster preparedness (SDG 13) and support (SDG 6) by identifying flood‐prone areas. Three high‐risk flood zones were identified: Neelum River–Shawai Nala confluence, Jhelum–Neelum rivers convergence at Domel and a low‐lying area near the Lohargali landslide. This study highlights the importance of integrating morphometric, geomorphological and geospatial techniques for effective disaster risk reduction (SDGs 11 and 13), climate‐resilient infrastructure (SDG 9), addressing SDG 6 and sustainable urban development, ensuring long‐term safety in tectonically active regions. Additionally, the methodology in this study, integrating multiple existing techniques, can be expanded for hazard assessment in other regions.

Radiometric-Assisted Heat Flow from Precambrian basement rocks, SW Nigeria: Implications on geothermal potential and geodynamic evolution

Integrated gravity-based structural characterization of the Sana’a Basin, Yemen using WGM2012 data, spectral analysis, and GM-SYS modeling

Hydrogeophysical assessment of groundwater and saltwater–freshwater interface in a quaternary– neogene coastal aquifer, Kilwa Kisiwani island, southeast Tanzania

This study aims to identify and explore new potential sites of groundwater resources using geophysical methods, and to demarcate the depth to the saltwater-freshwater interface. Kilwa Kisiwani Island is geologically covered mostly by Neogene and Quaternary alluvial sediments, sand and gravel. The geophysical techniques employed during the research include Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), and Transient Electromagnetics (TEM). The Island has the potential for groundwater occurrences, but the layer with fresh water is shallow and thin. Out of the 18 VES sites, 2 (11%) points have shown non-potential, but the remaining 16 (89%) of the VES sites have shown potential, and drilling has been recommended depending on the hydrogeophysical characteristics of each potential VES point. Out of the 16 TEM points, 4 (25%) have shown non-potential, but the remaining 12 (75%) have shown potential, and drilling has been recommended depending on TEM point-specific hydrogeophysical characteristics. Generally, geophysical results show the presence of freshwater lenses with a thickness range between 10 and 30 meters. The recommended drilling depth ranges between 10 and 30 meters below ground surface. The depth to saltwater-freshwater interface varies between 1 and 39 meters below ground surface.