| Title | A Correlation Study Beetween Volcanic Activities and Thermal Water Changes in Tangkuban Perahu Hydrothermal Prospect, Jawa Barat, Indonesia |
|---|---|
| Authors | Mahesa Pradana SAPUTRA, SURYANTINI |
| Year | 2015 |
| Conference | World Geothermal Congress |
| Keywords | magmatic volatile, δD, δ18O, Domas Crater, Ciater. |
| Abstract | Tangkuban Perahu is one of active volcano in Jawa Barat, Indonesia. The volcano and its surrounding thermal manifestation areas are classified as Volcanic Hydrothermal System that implies the reservoir fluid has strong association with volcanic activities from Tangkuban Perahu Volcano. In September 2012 based on observations of the Center for Volcanology and Geological Hazard Mitigation (PVMBG) there is increased activity at Tangkuban Perahu. The increasing activity was observed with seismographs and gas content of H2S and SO2. As the result, prior to exploitation of geothermal energy in this area, it is expected that significant variation on thermal manifestation occur due to natural volcanic activity. This paper will present the variation and the changes of hydrothermal waters at Tangkuban Perahu based on chemical changes in thermal manifestations. Hydrothermal water samples at Tangkuban Perahu collected in 1987, 2002, 2008 and 2012. The study shows that Kancah and Ciater thermal manifestation areas become sulfate water in 2012. Chloride content in Domas Crater have decreased more than 90 mg/L and the sulfate increased more than 1000 mg/L. Domas Crater water exhibit δD and δ18O enrichments from steam heating magmatic end member. This evolution is assumed because the additional of magmatic volatile such as H2S during the activity increased. Peripheral manifestations such as Batu Kapur, Batu Gede, Ciracas, Cimangu, Maribaya HCO3 increased. All waters have highly variable and unreliable geothermometer temperature, none of the fluid are at equilibrium with host rock. The result of this study can also become a baseline data for variation of thermal manifestation water due to natural volcanic activity. |