APPLICATION OF THE UCT METHOD ON VERTICAL DERIVATIVES IN DOWNWARD CONTINUATION CALCULATION FOR STRUCTURE IDENTIFICATION AND ITS APPLICATION IN WEST JAVA FIELD DATA

• Main Author: Ziqri Sabriaen, Abraar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81182
• Institution: Institut Teknologi Bandung

The processing and interpretation of gravity data is very important in various geophysical studies. One important method of processing potential field data is downward continuity, which helps reduce observational data to more interpretable data. However, downward continuity operations are often unstable when using data with noise. Therefore, cutting-edge methods are needed, such as the vertical derivative method with upward continuation used in downward continuation. The purpose of this study is to understand and calculate the use of the UCT method in downward continuation in synthetic models, compare the results with commercial software, and apply the UCT method to field data to assess its practical use. The results obtained show high stability and accuracy, especially on data with noise. The UCT method can map regional structures better than FAA maps. Analysis of the track shows geological details, including the horseshoe-shaped Bandung Basin opening to the west, surrounded by volcanoes. To the north, mountain complexes such as Mount Burangrang, Mount Tangkubanparahu, Mount Manglayang; east side there are Mount Cikuray, Mount Galunggung; south there are Mount Papandayan, Mount Cikuray; Mount Guntur - Mount Kamojang borders the Bandung and Garut Basins. Mount Gede – Pangrango and CiBed Basin were also identified, as well as the Lembang – Cimandiri Fault based on straightness patterns. This method is also compared with other anomalous separation methods based on their anomalous trends, namely Gaussian filter, Butterworth filter, and SVD. The comparison results show the straightness pattern on the downward continuity map and are in accordance with the geological map, and have a match of 86%. For comparison of straightness of UCT method with Gaussian filter 86% suitability, with Butterworth filter 80% suitability, and with SVD method 86% suitability. The results of this comparison show the effectiveness of the UCT method in enhancing useful signals, as well as clarifying smaller structures. Thus, the UCT method is reliable in gravity data processing, even on data with noise, with high stability and accuracy.