It’s always good to have a plan B. When you’re doing field work it’s usually good to have plans C, D, and E as well. Things just never go the way you think they’re going to. Our plan A is to make it out to the ice edge to collect natural frost flowers and young (freshly formed) sea ice. Dan finished an extensive survey toward the ice edge earlier in the week and the consensus is that the ice will have to thicken more before we can head out that way to sample. Most of the ice in McMurdo Sound right now is between 1.1 and 1.5 m thick (4-6 ft.), with the exception of some older “multiyear” ice at the south end of the sound that is several meters thick. Within a couple of kilometers of the ice edge the ice thickness decreases to 40-50 cm (15-20 in.). This is, in reality, plenty thick to drive on. McMurdo Station rules however require 76 cm (30 in.) of ice for vehicle travel. And with no helicopters to facilitate a rescue in case of a breakthrough (they start flying in October) there is little chance of getting permission to work outside of these rules. For access to the ice edge there is nothing to do but wait for the ice to thicken more, it won’t reach its maximum thickness until late in October.
In the meantime if we can’t reach the natural ice edge we can always try to make one that we can reach. In this case our “edge” will be a series of large holes where ice and frost flowers can form. We’ve tried this before in the Arctic without success; the opening salvos of a terrific series of blizzards covered the holes with snow, and then destroyed a tent that we tried to use to keep the holes snow free. We’ve got the time now to continually maintain the holes until a calm day (and hopefully frost flowers!). It’ll be cold, wet work but we’re ready for it!
Today Shelly and I scouted around for a place on the sea ice where the snow doesn’t seem to drift too deep and the ice is thick enough for the heavy equipment we will use to drill the holes. We think we’ve found a couple of good spots, so if the weather’s good tomorrow we’ll have a go at it…