High potential geothermal areas within the Rahat volcanic field, Saudi Arabia, from gravity data and 3D geological modeling

We present various geological models to examine the geothermal energy potential at the Rahat volcanic field, Saudi Arabia. The method involves the application of geophysical techniques of gravity and seismic tomography results to derive a 3D subsurface geological structure representing possible subsurface structural information beneath the northern Rahat volcanic field. Results show a secluded subsurface structure within the basement crust with low densities (< 2500 kg/m3) and a slightly high P-wave velocity, enclosed by a high density (> 2800kg/m3) and low P-wave velocity structure. Identified secluded subsurface structure could depict a magma intrusion within the basement and its depth proximity to the basalt deposition in the region signals the viability of this location for geothermal exploration. Deductions also show that the geothermal reservoir could be reached at starting depths of ~ 1.3 km, whereas its effect could be accessed at depths < 1 km. Within the geothermal active region of northern Harrat Rahat, this study has suggested possible locations with high potential for further geothermal exploration.