Recent GPS-based long wavelength crustal deformation revealed active postseismic deformation due to the 2006 Yogyakarta earthquake

We analyze the Global Positioning System (GPS)-derived strain rate distribution to investigate active crustal structure in Central Java, Indonesia, using ten years (2010-2019) continuous and permanent observation data. Central Java is the third-most populous province in Indonesia where postseismic deformation of devastating Yogyakarta earthquake in 2006 might influence the GPS data. The postseismic extensional response might overshadow the low contractional process due to active tectonics deformation. A decomposition method of a calculated strain rate shows a long wavelength feature with the extensional region in the vicinity of the 2006 Yogyakarta earthquake may reflect the postseismic process remain active. The short wavelength pattern is sharpening potential active tectonics dominated by oblique Northwest-Southeast dip-slip motion with East-West left-lateral sense. Our result demonstrates essential implications for assessing future seismic hazard potential within a low strain rate such as the Central Java region.