Interpretasi Lapisan Bawah Permukaan Dengan Metode Reduksi ke Kutub dan Pseudogravitasi Berdasarkan Data Geomagnetik Pada Daerah Sesar Lampung-Panjang (Gunung Sulah dan Gunung Banten)

Faults are areas where earthquakes and potential mass movement disasters are prone to occur. Mount Sulah and Mount Banten are located in the Lampung-Panjang fault area, which has the potential for mass movement due to this fault. This study aims to determine the subsurface rock arrangement using the magnetic method. Data processing begins with making corrections to obtain the total magnetic anomaly. The total magnetic anomaly is then subjected to upward continuation filtering, separation of residual anomalies, reduce-to-pole transformation, pseudogravity transformation, and 2D modeling. The pseudogravity filter results show similarities with the results of pole reduction. The use of RTP (reduce to pole) method correlated with pseudogravity transformation in processing magnetic anomaly data can interpret the subsurface of a research area. Pseudogravity transformation can be utilized as a supportive factor in making cross-sections on the RTP contour map in the 2D modeling process. The research results indicate that the study area of Mount Sulah and Mount Banten has low magnetic anomaly values, by observing the regional geological map of the research area, including the QTl formation, which has low magnetic susceptibility values and the presence of faults impacting mineral distribution and rock composition, ultimately affecting the magnetic susceptibility value in that area. Based on the 2D modeling, there are three subsurface layers. The first layer consists of clay rock with a susceptibility value of 0.025 SI, estimated to be part of the QTl formation. The second layer is composed of schist rock with a susceptibility value of 0.05 SI, estimated to be part of the Pzg formation. Finally, the last layer is the basement layer of basalt lava with a susceptibility value of 0.43 SI, estimated to be part of the Qhvp formation.