Fault Detection and Subsurface Model Based on Gravity Data in Pronojiwo, Lumajang, Indonesia

Understanding the subsurface structure is vital geophysical investigations, precisely local fault detection. Gravity anomalies were measured using satellite data from Global Gravity plus (GGMplus), and direct acquisition was used to achieve this goal. The residual anomalies range from -4.9 mGal to 3.6 mGal for the satellite and between -1.6 mGal to 0.94 mGal for direct acquisition. First Horizontal Derivative (FHD) and Second Vertical Derivative (SVD) analyses were performed based on the residual anomaly contrast. By integrating direct acquisition and GGMplus gravity data, this study aimed to analyze the existing local fault distribution in the research area. The preliminary result indicates the presence of faults with NW-SE orientation. Additionally, 2-D stratigraphic modeling includes three formations: andesitic lava, breccia, and tuff. The research provides a deeper understanding of subsurface structures using a combination of gravity data.