Grading the ice and snow is a never-ending process
McMurdo Station - Antarctica

Grading the ice runway. Contrary to how you think of a nice flat surface, snow and ice can rapidly build up a very rough and contoured surface of sastrugi - wind blown and sculptured snow that is easily up to a foot or more deep between peaks and troughs. This would make it all but impossible for aircraft to land on, so the surface needs constant flattening and levelling.