Segmentation of Sumatran Fault Zone in Tanggamus District, Lampung based on GPS Displacement and SRTM Data

Abstract

One of sources of earthquakes in Lampung Province is southern segment of Sumatran fault. The fault is used as consideration in generating hazard map which source comes from stress accumulation of crust which can be obtained by measurement of points in surface. Determining fault location is important for sustainable development in Lampung Province. Southern segment of Sumatran fault stretched on Kota Agung – capital of Tanggamus District, one of the cities with the oldest civilization in Lampung Province. The sedimentation of Kota Agung causes the delineation of Sumatran Fault Zone by using Digital Terrain Model conducted on previous research had flaw. GPS Displacement Data, Shuttle Radar Topography Mission (SRTM) Data and seismic activity are used as tools to determine the location of fault. SRTM Data has 30 meter resolution and measured in 2018. Seismic activity used in this research is obtained from USGS from last 100 years and is used as support data to determine whether the fault delineated with SRTM and GPS displacement is active. GPS displacement is derived from GPS coordinates measured periodically from 2006 to 2019. Displacement used in this research is horizontal displacement since Sumatran Fault is known as strike-slip fault that move on horizontal plane. The result resembles previous research. Location that has the highest possibility of Sumatran Fault Zone segmentation is identified as Sumatran Fault Zone segmentation on previous research named as West Semangko Fault, and East Semangko Fault, respectively. The only fault earthquakes occurred on location which is not identified Sumatran Fault Zone segmentation on previous research.