Perpustakaan Digital ITB

Indonesia is a geologically complex region situated at the south-eastern edge of the Eurasian Plate. It is bordered by tectonically active zones characterized by intense seismicity and volcanism resulting from subduction process. Sumatra also has active faults, such as Great Sumatran Fault. It extends the entire length of the island and coincides geographically with the volcanic arc through most of its length. Sumatran fault slip rate move with velocity from ?6 mm yr?1 near the Sunda Strait to ?25 mm yr?1 near the equator to ?50 mmyr?1 in the Andaman Sea. The influence of subduction process in southern Sumatra using GPS measurement is investigated. GPS data used are GPS data that observed periodically and continuously between 2006 and 2014 observed by National Geospatial Agency of Indonesia (BIG) and the Sumatran GPS Array (SuGAr) network. GPS observation data are processed by using scientific software: GAMIT 10.5. During the process, the effect of Great Sumatran Fault is removed. The displacement vector and velocity of every GPS observation stations on southern Sumatra affected by the subduction process between Indo-Australian Plate and Eurasian Plate is determined. Those GPS stations move northwest-westward linearly due to postseismic deformation of 2007 M7.7 Mentawai earthquake and 2012 M8.5 Indian Ocean earthquake. All regions in southern Sumatra are affected by subduction process between Indo-Australian Plate and Eurasian Plate based on strain analysis.