The Greenland ice sheet (GrIS) and its peripheral glaciers and ice caps (PGIC) have received a lot of attention with respect to its marine-terminating margin, where ice discharge contributes a significant amount to ice mass loss. However, a similar fraction of the mass loss is caused
by surface melt, leaving the ice predominately via the less studied terrestrial margins. Using existing ice masks and a lake dataset we extract the actual land-terminating sections,
making up 93.1% of the total GrIS (70 900 km) and PGIC (170 590 km) margin. The study provides evidence for the ability of the ice mask and ArcticDEM to capture margin
morphologies across approximately 84% of the landterminating margin correctly, even able to identify very steep margin morphologies at a regional scale. We identify 28.4% as near-vertical features over shallow terrain and a further 13.4% as steep (20–45°), which roughly corresponds to
an earlier estimate of 45% for ice cliffs. 17.3% of the landterminating margin are identified as shallow ramps (<20°). With geolocated morphologies, future studies will be able to identify to what degree past presence of lakes, bed topography or ice dynamics and past climate at and upstream of the margin can explain under which conditions the ice margin terminates in steep or shallow slopes. |