Evaluation Geothermal Potential Using Fault and Fracture Density, Petrography, and Water Geochemistry Analysis; Case Study in Ranau Lake, Lampung
| Main Authors: | Yonash Philetas Immanuel, Bevani Meydi Saptia, M. Hakim Al Amin, Fasha Nurkala Kalidasa |
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| Format: | Proceeding |
| Terbitan: |
, 2019
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/3333743 |
Daftar Isi:
- Conventional energy is currently decreasing continuously so that the development of alternative energy is needed. Promising alternative energy to develop is geothermal energy. Indonesia has a geothermal potential of 29.215 GWe, one of them which is on Ranau Lake. Administratively, Ranau Lake is located in West Lampung District, Lampung Province and South Ogan Komering Ulu District, South Sumatra Province. This study aims to identify geothermal potential based on fault and fracture density, petrography, and water geochemistry analysis. The methods used in this study are literature studies, geospatial analysis, field observations, laboratory analysis, and interpretation. The literature study uses a qualitative approach. Geographic Information System based geospatial analysis can be identified using the Fault and Fracture Density (FFD) method, lineament analysis of SRTM, and topographic data. By using those methods, the existing of fractures and possible levels of the areas that are recharged and discharge zones for geothermal might be predicted. Field observations include observing the appearance of rocks megascopically and the presence of geothermal manifestations. The results of the petrographic analysis of rock samples are dominated by mineral plagioclase, pyroxene, and biotite. Data that is analyzed water geochemistry is a manifestation that exists on the surface of the study area, namely hot spring. Water geochemistry data are integrated to determine the characteristics of water, temperature, and pH. Water sampling is carried out in areas of geothermal manifestations, such as Kota Batu, Seminung 1, Seminung 2, and Lombok. Surface temperature in the study area varies from 43-57°C and the pH value is 4.8-7.1. Laboratory analysis shows that water samples have high bicarbonate concentrations and include bicarbonate water types (HCO3). The presence of manifestations and the results of FFD analysis, it shows that the research area has the potential to become the next target of geothermal exploration.