Preliminary co-sesimic deformation model for Indonesia geospatial reference system 2013

Abstract

In the October 11st 2013, Indonesia introduced the new national geodetic datum which called as Sistem Referensi Geospasial Indonesia 2013 (Indonesian Geospatial Reference System 2013). This is a semi dynamic datum in natural, which the reference epoch define at 2012.0 and the coordinates change due to plate motion and earthquake was accommodate using a deformation model. One of the components of deformation model is co-seismic deformation due to earthquake. In this study we estimate the co-seismic deformation model based on GPS time series data and earthquake geometry parameter. We used 4 major earthquakes with the magnitude > 8 Mw that occurred in the Indonesia region since 2004. Our result shows the rmse of residual co-seismic deformation from both method (GPS and earthquake modeling) in the East and North components is 4.10 mm and 5.26 mm for Sumatra Andaman 2004 EQ, 46.68 mm and 178.92 mm for Sumatra Utara 2005 EQ, 140.42 mm and 171.00 mm for Sumatra Selatan 2007 EQ, and 14.29 mm and 9.73 mm for Wharton Basin 2012 EQ. The preliminary model should be improved by including several earthquakes to get best co-seismic deformation model to support IGRS2013.