ANALYSIS OF BATHYMETRIC DATA INFLUENCE ON TERRAIN CORRECTION IN GRAVITY DATA PROCESSING: CASE STUDY IN BANDA NEIRA AND KUR ISLAND REGIONS

• Main Author: Pratama Ibrahim, Yudith
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/75594
• Institution: Institut Teknologi Bandung

Terrain correction is one of the crucial stages in gravitational data processing. Previous research at Mount Pandan showed that terrain correction using topographic data resulted in a maximum correction of 14,74 mGal, while in a study in Taiwan Island, the inclusion of bathymetric data led to corrections up to 29,1 mGal. To accommodate terrain correction calculations in research areas in Indonesia, we utilized both DEMNAS topographic data and BATNAS bathymetric data in conjunction with gravitational data. DEMNAS topographic data has been widely used by researchers in gravity methods for terrestrial research areas in general, while the utilization of BATNAS bathymetric data is still rare, especially in terrestrial research areas near the sea. In this study, both data sets were employed in computational terrain correction using a combination of the sloped triangle method for the near zone, flat-topped square prism for the intermediate zone, and annular ring for the far zone. The research was conducted in the Banda Neira and Kur Island regions because between these two regions lies the complex undulation of the Weber Trench, making it suitable for demonstrating the contribution of bathymetric data to the total terrain correction.The results indicated that terrain correction calculations involving bathymetric data significantly contributed to the maximum total terrain correction values. The difference reached approximately 81,5 mGal in Banda Neira region and 69,8 mGal in Kur Island region. However, concerning correction patterns, the contribution of bathymetric data was inversely related to the contribution of topographic data when correlated with the topographic conditions. In regions further away from the Weber Trench, like Banda Neira, the inclusion of bathymetric data showed a terrain correction pattern similar to using only topographic data. However, in the case of Kur Island, which is closer to the Weber Trench, the inclusion of bathymetric data has a more significant impact and is capable of reversing the terrain correction pattern when using only topographic data. This makes bathymetric data worthy of consideration for high-resolution gravitational data processing, particularly in areas with extensive and deep trenches or seas nearby