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After two kilometers, we arrived to find only a sastrugi ridge, pockmarked wind deformations in the icy crust.

There’s brash ice, pancake ice, bullet ice, green ice, frazil, nilas, breccia, shuga, slush ice, rotten ice, pressure ice, grease ice, ice dust, shorefast ice, ice flowers, ice haycocks, ice saddles, floes, calf bergs, growlers, and sastrugi, to name just a few.

But the most difficult part of the journey, she said, was hauling her heavy load over sastrugi — wavelike speed bumps of snow and ice that can extend for miles.

All day, on skis, they each hauled sleds holding 220 pounds of gear across fields of ice waves called sastrugi.

By now, Roberts has guided or overseen numerous expeditions for Cooper, to the frozen ocean of the North Pole—where storms press the pack into “screw ice” and the wind forms sculpted ridges called sastrugi—and to the parallel universe at the extreme south.