Study of Crustal Structure Beneath Station Banjarnegara Indonesia (BJI) Based on Receiver Function Analysis

Abstract

Abstract We applied receiver functions (RFs) analysis to estimated the crustal structures beneath Station Banjarnegara, Indonesia (BJI). We selected teleseismic earthquakes with epicentral distance 30°-90° and magnitude greater than 6 (M > 6) that recorded from 3 component broadband seismograph at the station. We determined crustal thickness, S-wave velocity profiles and ratio of ν p/νs using nonlinear Neighborhood Algorithm (NA). We migrated RFs phase to depth by AK-135 global velocity models to identify the depth of the geological structure. From the Ps conversion phase and inhomogeneity of the arrival time, we detected the near surface has a strong anisotropy. We identified delay P phase near surface that associated with thick sedimentary layer in this area at about 2.5 km. Crustal thicknesses, ‘Moho depth’, beneath the station was estimated at depth 28-32 km. The high RFs amplitude phase that might be associated with the presence of Indo-Australian Slab was identified at a depth 140-160 km according to previous studies.