These two files (.csv) provide independent methods of quantifying subglacial roughness in Greenland, both calculated from radio-echo sounding (or ice penetrating radar) data collected by the Operation Ice Bridge programme using CReSIS instrumentation. They are an output of the Basal Properties of Greenland (BPOG) project (http://bpog.blogs.ilrt.org/), with funding from NERC grant NE/M000869/1. Roughness here, and in the wider literature, is defined as the variation in bed elevation (in the vertical) at the ice-bed interface, over a given length-scale. These two metrics calculate/quantify this variation in different ways: one shows topographic-scale roughness, calculated from the variation in along-track topography (bed elevation measurements derived from the radar pulse); and the other shows scattering-derived roughness, calculated from quantifying characteristics of each bed-echo (the return from the radar pulse at the ice-bed interface).

The geology underlying Thwaites Glacier plays a critical role in mediating ice flow in this region yet is extremely poorly known. Using new compilations of airborne radar, magnetic and gravity data, supported by published geological evidence, we have interpreted the subglacial geology of the Thwaites Glacier region. Here we provide the new data compilations, results of 3D inversions and vector components defining the lithological units on our new geological sketch map. British Antarctic Survey (BAS) National Capability contribution to the International Thwaites Glacier Collaboration (ITGC) (TJ), NERC Grant NE/S006621/1 (Geophysical Habitats of Subglacial Thwaites (Ghost)) (BK), Antarctic Science Collaboration Initiative program (Australian Government) (ST), European Space Agency (ESA) 4D Antarctica project (FF).