Gravity Disturbance Derived from Airborne Gravity and Its Geodynamics Interpretation of Sulawesi Island

Airborne gravity technique is more effective for geodetic and geophysical purposes especially over large and varied areas. However, the use of airborne gravity of Sulawesi Island has not been optimal, including the use of gravity disturbance data components compared to gravity anomaly data that is more commonly used. In this research, mapping of gravity disturbance was done based on airborne gravity data and subsequently was applied for interpretation of the geodynamics of Sulawesi Island region. Gravity disturbance value was obtained through the conversion of free-air anomaly. The results showed that the gravity disturbance of Sulawesi Island ranged from -206.10 to 352.58 mGal with a pattern similar to the free-air anomaly and two global models (EGM2008 and EIGEN-6C4). The difference with EGM2008 and EIGEN-6C4 was an average of -3.77 and -3.43 mGal with a standard deviation of ±26.59 and ±26.21 mGal. The large difference is probably due to a data gap and topographic area of the mountains. Map of gravity disturbance can also be used for the initial interpretation of active faults such as Palu Koro and Matano which showed a significant color deviation from the representation of significant differences in subsurface geological structures.