Winter 2018 time-series measurement of land-fast sea ice and sub-ice platelet layer thicknesses from electromagnetic induction soundings in McMurdo Sound, Antarctica

Ground-based electromagnetic induction (EM) time-series measurements of land-fast sea ice and sub-ice platelet layer thicknesses were carried out on land-fast sea ice in McMurdo Sound, Antarctica in winter (August 8 to 26 October) and late spring (November 4-18) of 2018. The EM data were acquired using a frequency-domain Geonics Ltd EM31-MK2 instrument mounted on the sea ice surface in winter and a sledge in late spring. The thicknesses of consolidated ice (sea ice plus the snow layer) and the sub-ice platelet layer were simultaneously retrieved from the EM31 measured response (i.e., Apparent Conductivity (AppCond) and Inphase (Inph)) using the forward modelling and inversion methods of Irvin (2018). Temporal variability in EM measured thicknesses detected the seasonal growth of land-fast sea ice and sub-ice platelet layer in winter, and shorter timescale variability related to strong offshore wind events in winter and the tides in late spring (Brett et al., 2024).