Supplement to: Brett, Gemma Marie; Irvin, Anne; Rack, Wolfgang; Haas, Christian; Langhorne, Patricia J; Leonard, Greg 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, https://doi.org/10.1029/2019JC015678