Comparative study on vertical deformation based on GPS and leveling data

The development of GPS (Global Positioning System) technology has led to increasingly widely and successful applications of GPS surveys for monitoring crustal movements. However, multi-period GPS survey solutions have not been applied in monitoring vertical crustal movements with normal backgrounds. In this paper, we carried out a comparative study on the vertical deformation of the comprehensive profile of the cross-fault zone in Shanyin, Shanxi province, China, based on GPS and precise leveling observation data for multiple time periods. The vertical deformation rates observed with repeating GPS survey are obviously different (over 20 mm/y at some sites) from those with repeating leveling survey within a relatively short period. However, the deviations in the vertical displacement between GPS and leveling in a long-term survey (over three years) showed good consistency at 3-4 mm/y at most sites, on GPS forced offset surveying and fixed survey instruments in a long-term survey (over three years). Therefore, GPS vertical displacement results can be applied to the study of vertical crustal movements.