Surface ice immobilizes beach and dune sands by preventing the wind from reaching the sand grains.

Unlike snow, surface ice is generally too resistant to wind forces to be transported away from a location. Areas of surface ice can thin, shrink and disappear over time as a result of sublimation or melting followed by evaporation.

Surface ice forms where water from waves, melting snow/ice and rain freeze onto beach and dune surfaces. Often meltwater cannot drain into the frozen ground so it collects in depressions where it freezes when temperatures fall.