Sastrugi
Videos
Sastrugi, or zastrugi, are features formed by the erosion of snow by wind. They are found in polar regions, and in snowy, wind-swept areas of temperate regions, such as frozen lakes or mountain ridges
Wind sculpted snow near South Pole Station, forming sastrugi features.
Large sastrugi seen in radar image around the south edge (left side) of Lake Vostok in Antarctica (RADARSAT, NASA). White and black colors on sastrugi are not lights and shadows; they demonstrate a difference in radioreflectivity of snow deposits on the windward and leeward sides of a sastruga.
Sea ice
Videos
Sea ice forms as seawater freezes. Because ice is less dense than liquid water, it floats on the ocean's surface. Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Mu
Sastrugi
…of a ridge, the base erodes faster than the top, producing a shape like an anvil tip pointing upwind. Sastrugi are more likely to form on first-year sea ice than on multiyear ice. First-year ice is smoother than multiyear ice, which allows the wind to pass uniformly over the surface without topographic…
Broken pieces of Arctic sea ice with a snow cover
Nilas in Baffin Bay
Aerial view showing an expanse of drift ice offshore Labrador (Eastern Canada) displaying floes of various sizes loosely packed, with open water in several networks of leads. (Scale not available.)
Aerial view showing an expanse of drift ice consisting mostly of water. (Scale not available.)