Geophysical forensic for surface fault investigation in Padang, West Sumatra, Indonesia

The West Sumatra region is an earthquake-prone region with a high-intensity scale. One of the earthquakes occurred on September 28, 2009. The earthquake triggered a ground movement in the form of surface faults and liquefaction phenomena. Surface fault structures are challenging to detect due to tropical climatic conditions with high weathering and dense settlements. Several measurements of Ground Penetrating Radar are carried out to study the geological structure below the surface after an earthquake. The study was conducted around the city of Padang. Data processing is performed using MATGPR software. Based on the results of the GPR analysis, several subsurface structures were found due to the Padang earthquake that were continuously and detected up to the surface. Some subsurface structures detected by GPR are not continuous to the surface. There is a possible relationship between the phenomenon of surface faults and liquefaction.