Revealing the contemporary kinematics of Antarctic plate using GPS and GRACE data

Abstract

Revised horizontal and vertical plate velocities of the Antarctic conti nent in ITRF2008 and the impact of elastic and viscoelastic deformations over the continent due to Antarctic Ice Sheet (AIS) variations are simultaneously estimated using GPS and GRACE data for the period 2005–2015. The improved GPS time series and resulting horizontal and vertical velocities indicate that East Antarctica is subsiding significantly, whereas West Antarctica is experiencing uplift with tran sitional subsidence along the Trans-Antarctic Mountain ranges. According to the ongoing elastic deformation and AIS mass variations from GRACE data, the East Antarctic area is subsiding at a rate of 1 mm/yr. The elastically corrected or GRACE corrected vertical deformation also exposes the deformation patterns associated with the viscoelastic vertical deformation in terms of East Antarctica subsidence and West Antarctica upliftment. The GIA model values also agree well with elastically corrected vertical motions when validated with elastically uncorrected and corrected GPS vertical velocities. Hence we reveal that the outcome of the elastically corrected vertical deformation in the Antarctic region is very well connected to the long-term viscoelastic changes akin to AIS mass variations.