FIGURE 2 



OBSERVED SEA ICE CONDITIONS FOR THE DATES INDICATED DURING THE 1981 IN- 

 TERNATIONAL ICE PATROL SEASON. TOTAL CONCENTRATIONS ARE GIVEN IN 

 TENTHS. THE KEY TO AND THE DESCRIPTION OF THE TYPES OF ICE ARE GIVEN 

 BELOW. SEA ICE SYMBOLS CONFORM WITH WORLD METEOROLOGICAL ORGANIZA- 

 TION STANDARD SYMBOLS. COMBINATIONS OF THE SYMBOLS ARE USED TO 

 INDICATE MIXTURES OF ICE TYPES. 



**: New Ice. General term for recently formed SEA ICE; composed of ice crystals which 

 are only weakly frozen together. 



= : Young Ice. SEA ICE in transition between nilas and first year ice; 10-30 cm in 

 thickness. 



>s^ : First Year. SEA ICE of not more than one winter's growth, developing from young 

 ice; thickness 30 cm to 2 m. 



Old Ice. SEA ICE which has survived at least one summer's melt. Most topographic 

 features are smoother than first year ice. 



ty^ : Patches, Strips and Belts. Patches. An area of PACK ICE less than 10 km across. 

 Belts. A large feature of PACK ICE arrangement; longer than it is wide; from 1 km to 

 more than 100 km in width. Strips. Long narrow area of PACK ICE about 1 km or less 

 in width; usually composed of small fragments detached from the main mass of ice, and 

 run together under the influence of wind, swell or current. 



SEA ICE: Any form of ice found at sea which has originated from the freezing of sea water. 



PACK ICE: Term used in a wide sense to include any area of sea ice, other than fast ice, no matter 

 what form it takes or how it is disposed. 



21 



