These data were aquired with a Terrestrial Radar Interferometer overlooking the grounding zone of Priestley Glacier, Antarctica. The time series contains line-of-sight velocities averaged over 3 h over an approximately 8 day period in November 2018.Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over >10 km upstream of the grounding line. Tidal flexing is observed >6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and <40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing.

Time series of line-of-sight flowfields averaged over approximately three hours.Data were taken with a Terrestrial Radar Interferometer in November 2018 at the grounding zone of Priestley Glacier, Antarctica– The Zip Archive contains 288 Geotiff in South polar stereographic projection– Each raster has 4027 x 4746 entries– The file name details the approximately 3h time inverval of aquisition with Stack_YYYYMMDD_HHMMSS_YYYYMMDD_HHMMSS marking the beginning and end of the time interval, respectively.- The line of sight velocities are given in meters per year