Fig. 1: Observations of subglacial lake drainage and surface outburst.
From: Outburst of a subglacial flood from the surface of the Greenland Ice Sheet
a, True colour composite Landsat-8 scene acquired on 22 July 2014 before the subglacial-outburst flood (SL1 indicates the location of a supraglacial lake referred to in the text; white boxes locate the regions shown in b, c, e, and f). Inset: the location of a (red box) relative to the Harder Glacier (Gl.) and Victoria Fjord. b, Three-dimensional shaded relief of the collapse basin mapped before lake drainage, using 2-m-resolution ArcticDEM data acquired on 9 July 2012. c, Three-dimensional shaded relief of the downstream region on 9 July 2012. d, True colour composite Landsat-8 scene acquired immediately after the subglacial lake drainage and surface outburst on 1 August 2014. e, Three-dimensional shaded relief of the collapse basin acquired on 28 April 2015, after the subglacial lake drained. f, Three-dimensional shaded relief of the same downstream region on 28 April 2015, showing ice fractures and uplifted ice blocks. Landsat-8 data in a and d from https://earthexplorer.usgs.gov and ArcticDEM data in b, c, e and f from https://data.pgc.umn.edu/elev/dem/setsm/ArcticDEM.
