Preliminary Result of a Regional Hydrothermal Alteration Analysis in the Dieng Volcanic Area Using Satellite Magnetic Anomaly Data Hanif Izzuddin Zakly (1,2), Mohammad Hasib (2), Adi Susilo (1*), Alamsyah M. Juwono (1), Arif Nur Rohman (1,2), Faradilla Nur Sarianna (2,3), Fathia Matondang (2,3), Putu Billy Suryanata (2), Aditya Pratama (2), Nia Kurnia Praja (2), Dini Nurfiani (2), Siti Zulaikah (4)
1) Departement Physics, Faculty of Science, Technology and Mathematics, Universitas Brawijaya, 65145 Malang, Indonesia
*adisusilo[at]ub.ac.id
2) Research Center for Geological Disaster, National Research and Innovation Agency (BRIN), 40132 Bandung, Indonesia
3) Geophysics Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung,40132 Bandung, Indonesia
4) Departement Physics, Faculty of Mathematic and Natural Sciences, Universitas Negeri Malang, 65145 Malang, Indonesia
Abstract
Dieng is one of the active and geologically complex volcanic regions in Central Java. The area contains various volcanic features, including craters, fumaroles, and solfataras, which are widely distributed across the region. Several of these features have developed into geotourism destinations, while others are associated with geothermal manifestations that support the potential use of renewable energy, particularly around Sikidang and Sibanteng Craters. Despite the significant geothermal potential of the Dieng Volcanic Area, the spatial distribution of hydrothermal alteration zones has not yet been mapped in detail. Therefore, this study aims to analyze and regionally map hydrothermal alteration zones in the Dieng Volcanic Area using satellite-derived magnetic anomaly data. Variations in magnetic anomaly values within the Dieng Volcanic Area can be used to identify the distribution and possible extent of alteration zones. The analysis of total magnetic anomaly data shows that magnetic anomaly values in the Dieng Volcanic Area range from -190.03 to 312.87 nT. Low magnetic anomalies, ranging from -190.03 to -64.31 nT, are represented by dark blue to light blue colors on the anomaly map. These low-anomaly zones are distributed around Mount Bismo, Seroja, and Pakuwaja, and also include geothermal manifestation areas such as Telaga Merdada, Sikidang Crater, and Sibanteng. The alteration zone is also interpreted to be connected with Mount Sindoro, located to the east-southeast of the Dieng Volcanic Area. This zone is likely associated with andesitic rocks that have undergone demagnetization due to hydrothermal alteration processes. These results provide preliminary evidence of hydrothermal alteration zones within the Dieng Volcanic Area and may serve as a useful reference for future geophysics-geological exploration.
Keywords: Dieng Volcanic Area, Hydrothermal Alteration Zone, Magnetic Anomaly
