Abstract

Research on the analysis of the source mechanism of the mainshock and aftershock events of the May 27, 2006, Yogyakarta earthquake, which is thought to have originated from the Opak fault and analysis of receiver function data to model the subsurface velocity P of the Central Java subsurface, to obtain a geological form model of the Opak fault. This research aims to support the development of the Yogyakarta Aerothroppolis area in terms of disaster analysis. The data used in this study are remote Teleseismic receiver function data from the MERAMEX station installed in 2004, and data for the Bantul earthquake event and its aftershock event in 2006. The results obtained from the analysis are that the Yogyakarta area is shaped like a half-graben close to Yogyakarta International Airport. The fault that separates the western part of Yogyakarta is still not identified. Based on the results of the rupture process analysis of the source along the Opak fault plane, some zones have not yet released their energy. The distribution of aftershocks due to the mainshock on 27 May 2006 is spread around the Opak fault, which is heading North-South, and West-East, which is thought to have activated the minor fault to the east of the Opak fault. The opak fault rupture area can be analyzed to have a Low Anomaly velocity P value from the receiver function data and is the same as the aftershock event obtained.