Abstract
Here, we present drill hole measurements of land-fast sea ice and sub-ice platelet layer thicknesses, fast ice freeboard, and snow depth collected at 6 drill sites distributed over a 60 km^2 fast ice area in Gerlache Inlet, north Terra Nova Bay, western Ross Sea, Antarctica between 3 and 7 November 2021. At each site, five holes were drilled in the fast ice at the centre and end points of two cross‐profile lines, each 30 m long. Sea ice and SIPL thicknesses were measured with a suspended thickness probe and metal bar using the procedure described in Price et al. (2014). Snow depth measurements at centimetre accuracy were made at the drill holes using a metal ruler. Sea ice freeboard (i.e., the height of the sea ice surface above sea level) was measured in each of the drill holes. The average value for each parameter at a field site was calculated from the five drill hole measurements to provide a representative measurement over the 30 m cross-profile fast ice area. The drill hole measurements were used to underpin spatial distribution surveys of the aforementioned parameters, to calibrate electromagnetic induction forward and inverse models, and to ground-validate satellite altimetry assessments of fast ice freeboard and derived ice thickness.