Subglacial water flow and ice dynamics during glacial lake outburst floods observed from space

The data in this depository are presented and described in: Magnússon, E., Drouin, D., Pálsson, F., Jóhannesson, T., Belart, J. M. B., Wuite, J., Tolpekin, V., Hannesdóttir, K., Berthier, E., Sigurðsson, G., Einarsson, B., Ófeigsson, B., Nagler, T., Gudmundsson, M. T. & Högnadóttir, Subglacial water flow and ice dynamics during glacial lake outburst floods observed from space. Nat Commun 17, 3471 (2026). https://doi.org/10.1038/s41467-026-70428-w Please use the above reference when citing these data. The data are in three zip-files: 3D_Velocity.zip, with 3-D velocity fields in three sub-folders deduced from ICEYE satellite radar images of Skeiðarárjökull in S-Vatnajökull ice cap (Iceland) during outburst floods from Grímsvötn subglacial lake in December 2021 (from ascending and descending tracks) and October 2022 (from descending track), as well input data that were used to calculate the velocity fields in sub-folders. DEMs.zip, with DEMs of the glacier surface and the bedrock for the Grímsvötn area and vicinity. The glacier surface is from Pléiades stereo images acquired on 18 October 2022. The bedrock DEM was interpolated using data described in the study referenced above. DEM_difference.zip, with elevation–difference maps of Grímsvötn and vicinity for nine consecutive periods in 2018–2022. The difference maps were calculated using one digital elevation model (DEM) from the ArcticDEM archive (Porter, C. et al. ArcticDEM, Harvard Dataverse, V1. https://doi.org/10.7910/DVN/OHHUKH, 2018) and 8 DEMs derived from Pléiades satellite stereo images. The origin of the DEMs used for calculating each elevation difference map is indicated in file names. All raster data are in geotif-format, using the ISN93 Lambert geographical projection, EPSG 3057, of the Natural Science Institute of Iceland (formerly the National Land Survey of Iceland). DEMs are in the ISH2004 vertical datum (in meters above sea level) of Natural Science Institute of Iceland. The velocity raster files have 100x100 m cell size, whereas DEMs and elevation-difference maps have 20x20 m cell size.