#TITLE_ALTERNATIVE#

• Main Author: Andi Putra P. S. (NIM :10211058), Bryan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26158
• Institution: Institut Teknologi Bandung

The gravity method measures the variations of earth's gravitational acceleration on the surface to detect the density’s distribution of the mass below the surface. In this study, gravity method used to know the density's distribution below the ‘X’ region. In the process of measuring gravity data in the field, this method uses gravitymeter to measure the gravity value at each measuring station through the looping process. The obtained gravity data is then reduced to produce a Complete Bouguer Anomaly value. The Bouguer anomaly of the ‘X’ region varies from 92.5385 mGal to 112.76 mGal. Separation of regional anomaly and local anomaly using the Trend Surface Analysis method. The separation by the second degree polynomial yields a better local anomaly value, ranges from -7.4781 mGal to 11.7343 mGal. The local anomaly is then mapped in two-dimensional map and A-A ', B-B', C-C', D-D' paths are the representation for analyzing the sub-surface density structure of area ‘X’. Forward modelling on path A-A’ produces a density contrast of -0.807 gr / cm3, the path B-B' produces a density contrast of -0.824 gr / cm3, path C-C' produces a density contrast of -0.931 gr / cm3, and path D-D’ produces a density contrast of -0.934 gr / cm3. Based on the value of the density contrast, subsurface's density of the ‘X’ region estimated to 1.9057 gr / cm3 to 2.0327 gr / cm3. The sub-surface’s structure of ‘X’ region indicated as a pyroclastic-volcanic rock structure (volcanic breccia, tuff).