MODELING AND INVERSION OF 2D GRAVITY ANOMALY IN BASIN USING THREE-POINT RULES GAUSS LEGENDRE QUADRATURE METHODS AND LEVENBERG MARQUARDT

• Main Author: DONA SARI (NIM : 20216017), SILVIA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30956
• Institution: Institut Teknologi Bandung

The basin structure can be identified based on geophysical analysis. Geophysical analysis uses geophysical data based on certain physical parameters which can then be interpreted to create a subsurface geological model. One of the physical parameters to be determined is the density value to depth. An effective geophysical method used for such purposes is the gravity method. The gravity method can be used for this purpose, by measuring the gravity anomaly on the surface due to the contrast of density between the bedrock and the basin filler material, the basin geometry and the surface topography. The gravity anomaly modeling by the basin structure is based on the formulation of Abdeslem (2003). The assumption used is that the density contrast varies with polynomial depth. The Abdeslem formulation is used to integrate the depth variables so that they only fall within the distance variables. The results of the Abdeslem Formulation can be integrated using the Gauss-Legendre Quadrature method. Future modeling generates synthetic data that is validated by Levenberg Marquardt inversion. Synthetic data is used to determine the subsurface basin model with the Fourier approach. From the modeling results it is seen that the surface topography response is very dominant compared to the geometry of the base rock. This is because when the geometry of bedrock underground under the surface, the effect is less influential as it is further away from the surface.