We don't have synonyms for zastruga yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are sastruga, zastrugi and sastrugi.
(n) :
Alternative form of sastruga. [Any of a series of long, wavelike ridges or grooves formed on a snow surface by the wind, especially in polar plains, and surfaces of ice-covered lakes/seas. These dunes of snow may be blown across the plains like wind-driven waves.]
(n) :
Alternative form of sastruga. [Any of a series of long, wavelike ridges or grooves formed on a snow surface by the wind, especially in polar plains, and surfaces of ice-covered lakes/seas. These dunes of snow may be blown across the plains like wind-driven waves.]