Modeling Crustal Structure in West Sumatera Using Teleseismic Receiver Function

Abstract

Indonesia is located between three significant plate confluences that play a role in creating a subduction zone. Sumatra, one of Indonesia’s provinces, is located near the collision of the Eurasian Plate, the Indo-Australian Plate, and the Pacific Plate. The Semangko Fault, the Mentawai Islands, a chain of non-volcanic forearc islands, and active faults that induce earthquakes and landslides are all produced by subduction zones on Sumatra Island. The receiver function approach was developed to identify the discontinuity limits of the Earth’s structures, such as the crust and mantle, from teleseismic events. The information in this study comes from 25 temporal and 1 permanent station in West Sumatra and the time period between 2007 and 2009 from the IRIS data station. The earthquake data was taken from teleseismic earthquakes from the three components of seismic stations using criteria arc distances between 30° and 90° and magnitudes ranging from 6.0 to 10.0. This research aims to determine how crustal thickness is distributed and what effect regional geological structure has on crustal thickness. According to the early results of the study, the estimated range of crustal thickness in the research region is 27.11–32.48 km, and the range of Vp/Vs ratio values is 1.70–2.19. The direction of crustal thickness thickening in the area was likewise East-South.