High-resolution ice thickness and bed topography of a land-terminating section of the Greenland Ice Sheet

Abstract

Abstract. We present ice thickness and bed topography maps with a high spatial resolution (250-500 m) of a land-terminating section of the Greenland Ice Sheet derived from ground-based and airborne radar surveys. The data have a total area of ∼ 12 000 km 2 and cover the whole ablation area of the outlet glaciers of Isunnguata Sermia, Russell, Leverett, Ørkendalen and Isorlersuup up to the long-term mass balance equilibrium line altitude at ∼ 1600 m above sea level. The bed topography shows highly variable subglacial trough systems, and the trough of Isunnguata Sermia Glacier is overdeepened and reaches an elevation of ∼ 500 m below sea level. The ice surface is smooth and only reflects the bedrock topography in a subtle way, resulting in a highly variable ice thickness. The southern part of our study area consists of higher bed elevations compared to the northern part. The compiled data sets of ground-based and airborne radar surveys cover one of the most studied regions of the Greenland Ice Sheet and can be valuable for detailed studies of ice sheet dynamics and hydrology. The combined data set is freely available at

Subglacial water drainage, storage, and piracy beneath the Greenland ice sheet

“…Hydraulic potential is a steady state proxy for routing of subglacial water [Shreve, 1972] and is the sum of the pressure potential from the overburden ice and the elevation potential. We used a 250 m resolution ice thickness DEM from the compiled radar data sets of Lindbäck et al [2014], supplemented with the mass conservation model of Morlighem et al [2014] at 150 m resolution. We calculated the bed elevation from the latter by subtracting the ice thickness from the GrIS Mapping Project (GIMP) surface elevation model at 30 m resolution .…”

Surface elevation changes during 2007–13 on Bowdoin and Tugto Glaciers, northwestern Greenland

“…Compared with velocity, ice thickness is more difficult to measure and data are sparse for most of the outlet glaciers. The quality of GrIS bed elevation maps is improving (Bamber and others, 2013; Lindbäck and others, 2014). For example, airborne ice radar and satellite-derived ice motion data are combined to compute precise GrIS bed topography based on mass conservation (Morlighem and others, 2013).…”

Structural glaciology of Isunguata Sermia, West Greenland

“…This trough extends ∼20 km upglacier and has a primary influence on ice flow and subglacial hydrology (Lindbäck et al, 2015). Ice thickness varies from <100 m at terminus to around 800 m some 45 km from the terminus, with thickness increasing to >1500 m 100 km inland (Lindbäck et al, 2014). Borehole thermistor measurements reveal that englacial ice with temperatures down to −12°C is advected into IGS from the ice sheet interior.…”