Floating mass of ice, about 80% of which is submerged, rising sometimes to 100 m/300 ft above sea level. Glaciers that reach the coast become extended into a broad foot; as this enters the sea, masses break off and drift towards temperate latitudes, becoming a danger to shipping.
The central band was originally red. It was changed to blue to express solidarity with the Allies during World War I. Effective date: 28 September 1917.