Ice-free Antarctica - A union of rock outcrop layers derived from imagery collected from 1960-2020

This geotiff represents the union of the medium-resolution remote sensing-derived rock outcrop layer for Antarctica (Gerrish et al. 2020) and the high-resolution Landsat-derived rock outcrop layer (Burton-Johnson et al. 2016). This was to ensure that as much ice-free ground as possible was covered by the typology, as both layers have minor known omissions of ice-free areas due to imperfect methodology or incomplete data. The union of these two layers was masked to land areas using a high-resolution Antarctic coastline polygon from the SCAR Antarctic Digital Database to exclude areas where the rock outcrop layers do not correspond to land due to misalignment with the coastline. The imagery was collected approximately from 1960 to 2020.Gerrish L, Peter TF, Cooper P (2020) Medium resolution vector polygons of Antarctic rock outcrop (7.3). https://add.scar.org/ Burton-Johnson A, Black M, Peter TF, Kaluza-Gilbert J (2016) An automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat 8 imagery: A new rock outcrop map and area estimation for the entire Antarctic continent. Cryosphere 10:1665–1677. https://doi.org/10.5194/tc-10-1665-2016