Perpustakaan Digital ITB

Bali and Nusa Tenggara are surrounded by some tectonic activities such as subduction in the south of Bali, Lombok and Sumbawa, collision in the south of Sumba and Flores, and back arc thrust in the north of Bali and Flores. These activities occurred resulted in strain and stress temporally and spatially causing deformation. Geodetic Measurement observed the deformation using GPS. Based on GPS measurement, it would be derived data of deformation geometrically. The data was processed using GAMIT 10.5 resulting daily position of observed points. After processing data using GAMIT 10.5, there were several steps to be done to fill the research objectives. This research was intended to determine the velocity and the vector of observed point toward Sundaland Block, determine strain, and estimate the transition zone between subduction and collision zone from Bali to Nusa Tenggara. The results of data processing showed that GPS stations at Bali and Nusa Tenggara were moving at range of 6.84 ± 0.26 mm/year to 48.15 ± 0.17 mm/year toward Sundaland Block. Strain pattern in Bali indicated subduction zone in the south and strain pattern in Flores-Timor indicated collision zone in the south. The velocity and strain also showed the transition zone between subduction and collision, which was indicated to occur in the south of the area. However, this estimation needed further research because it was just a preliminary study.