Non-linear crustal deformation modeling for dynamic reference frame: a case study in Peninsular Malaysia

Series of major big earthquakes struck the Sundaland platelet since December 2004 due to convergence between Indian and Australian plates along its western and southern boundaries. Consequently, the plate has been undergoing significant co-seismic and post-seismic afterslip deformation effecting national geodetic reference frame for countries in the region such as Malaysia. The deformation is causing errors in Global Navigation Satellite System (GNSS) satellite measurements due to incompatibility between ground and satellite coordinates. In addition, the afterslip deformation exhibits ongoing non-linear motion of land mass which further complicates the maintenance of the geodetic frame. This paper investigates spatio-temporal crustal deformation due to Mw >7.9 earthquakes that is affecting geocentric reference frame and geospatial accuracy in Peninsular Malaysia. The fundamental work was modelling the co-seismic and post-seismic deformation to account for time dependency of reference frame. The study has found that afterslip deformation model has minimized the effect of non-linear motion on geodetic network in the order of better than 2cm. The work is significant in view of improving the stability of reference frame in Malaysia