This dataset contains a map of ground movements covering the Afar Rift Zone in Ethiopia, Eritrea, and Djibouti for the time period between October 2014 and August 2019. The Afar region is located where three tectonic plates are pulling apart, creating rift segments which are 50-100 km long. Surface deformation on these segments is not constant in time, with episodes of rifting occurring periodically and magma intrusions causing sudden ground movements. We use frequent Sentinel-1 satellite Interferometric Synthetic Aperture Radar (InSAR) observations to measure surface displacements through time across the whole region. We relate these to ground based Global Navigation Satellite Systems (GNSS) observations and combine data from different satellite tracks to produce maps of the average surface velocity in three directions (perpendicular to the rift zone, parallel to the rift zone, and vertical). The continued observation of these time-varying ground movements is important for understanding how continents break up, with data here providing evidence of how tightly focussed extension is around the rift segments and of the subsurface magma movement at several volcanic centres.

This dataset has been produced as part of the Theme 5 (Cryosphere and Polar Oceans) in the National Centre for Earth Observation which aims to use new EO data to quantify changes in the mass balance of the cryosphere and to develop new models to represent the relevant processes in coupled climate prediction models. This dataset holds timeseries of Greenland glacier velocity fluctuations as maps for the period March-July 2011. The 37 velocity maps were derived from SAR data acquired during the 2011 ERS-2 3-day campaign. The velocity maps are 3-day velocity averages and are given in meters per year (m/y) (magnitude values). The name of the velocity files provides the start and end date of each 3-day period. The velocity fields were transformed to map coordinates using the GLAS/ICESat 1 km Laser Altimetry Digital Elevation Model of Greenland which is provided at Polar Stereographic grids (DiMarzio, J., Brenner, A., Schutz, R., Schuman, A. & Zwally, H.J. (2007)): GLAS/ICESat 1 km laser altimetri digital elevation model of Greenland. Boulder, Colorado USA: National Snow and Ice Data Centre. Digital media).