Sastrugi

Sastrugi, also spelled zastrugi, are ridges and sculpted shapes in snow cut by the wind. They appear in polar regions and in snowy, wind-swept parts of temperate regions such as frozen lakes and mountain ridges. Their typical form has upwind-facing points that resemble anvils and slowly move downwind as the surface erodes, lying along ridges parallel to the prevailing wind, steep on the windward side and sloping on the leeward side. Smaller versions are called ripples or wind ridges. Steady wind first drifts loose snow into mounds, the drifts consolidate when winds slacken, and later winds carve them into sastrugi. They form more readily on smooth first-year sea ice than on multiyear ice. Large sastrugi are tiring for skiers and snowboarders to cross and can break equipment. The word is a Russian plural.