Identification of geological structure based on gravity satellite and seismicity data in Kepahiang geothermal prospect area

Kepahiang geothermal prospect area is located in Bengkulu, in the western part of Sumatra Island. There are surface manifestations in Kepahiang, such as Sempiang fumarole, Babakan Bogor hot spring, and Sindang Jati hot spring. The existence of geothermal manifestations cannot be separated from the role of geological structure. Thus, in this study, geological structures were mapped using gravity and seismicity data. This study uses data from the GGMPlus satellite gravity which is corrected by free air and seismicity data from 1951-2020. Gravity derivative analysis was then used to map the distribution of structures in the Kepahiang geothermal prospect area. Meanwhile seismicity data were used to help identify the mapped structures are still active or not. The results of the gravity data and seismicity data analysis show that geological structures of the Kepahiang have NW-SE lineament trend. These geological structures occur close to manifestations locations, which indicates that these structures are fluid pathways from below to surface manifestations. In addition, there have been several recent seismic events that indicating the structure is still active.