Ground-based electromagnetic induction (EM) surveys of sea ice and sub-ice platelet layer thicknesses were carried out on land-fast sea ice in McMurdo Sound, Antarctica in November of 2011, 2013, 2016 and 2017. The EM data was acquired using a frequency-domain Geonics Ltd EM31-MK2 instrument mounted on a sledge and towed by skidoo.The thicknesses of total ice (sea ice plus the snow layer) and the SPL were simultaneously retrieved from the EM31 measured response using the processing method of Irvin (2018) (refer to pages 89-98). A correction for the addition of the snow layer was applied to obtain to EM measured Sea Ice (emSI) thickness according to section 2.3 of Brett et al. 2019.

Supplement to: Brett, Gemma Marie; Irvin, Anne; Rack, Wolfgang; Haas, Christian; Langhorne, Patricia J; Leonard, Gregory H (2020): Variability in the Distribution of Fast Ice and the Sub‐ice Platelet Layer Near McMurdo Ice Shelf. Journal of Geophysical Research: Oceans, 125(3), e2019JC015678