Relocation of Earthquake Hypocenter Using Double-Difference Method in Western Part of Sumatera

Abstract

The western part of Sumatra has a fairly complex tectonic setting where there is a convergent meeting between the Indo-Australian plate and the Eurasian plate. These plates form a subduction zone and also the Sumatran Fault. The subduction zone and the Sumatran Fault cause many earthquakes in western Sumatra. This study will identify the location of the earthquake hypocenter, which is quite accurately obtained by relocating the hypocenter and making a cross-section in order to analyze the subduction zone and the Sumatran Fault. Hypocenter relocation can be done using the double difference (DD) method using the hypoDD program. This study used data on the arrival time of P and S waves from BMKG in the range of January 2016 to December 2020. The results of the relocation indicate that contains several earthquakes in groups with an average depth of fewer than 60 km that is close to the main source of the earthquake, namely the subduction zone and the Sumatran Fault, so it can be said that this area has a high level of seismicity.