GUIDE TO THE KEY AND THE ICE GLOSSARY 



To make an intelligent approach toward an understanding of ice, it is 

 necessary to know first which ice features can and should be observed. 

 Obviously some order or system is required so that thinking can be un- 

 cluttered and properly directed. The following key is a collection of the 

 more significant ice terms assembled into homogeneous, convenient groups. 

 A portion of the glossary is built around each group. The key is no mere 

 assemblage of ice terms, but rather a framework or nucleus devised for 

 building eventually a complete ice terminology with provision for ice 

 elements and ice processes as yet undiscovered. 



The key has five large divisions : Sea Ice, Land Ice, Lake Ice, River 

 Ice, and Special Terms. The large divisions are then subdivided as, for 

 example, Sea Ice into Floating Ice, Fast Ice, and Related Features. 

 Each of these is likewise further subdivided. Thus, Floating Ice is 

 described according to its Concentration, Size, Age, and Topography. 

 Finally these latter categories are broken down into elemental groups as, for 

 example, Concentration into Open Water, Scattered Ice, Broken Ice, 

 Close Ice, Consolidated Ice, and Transitional States. 



The key can be considered a basic vocabulary of the more important, 

 preferred ice terms which are defined and elaborated upon in the body of 

 the glossary. These particular terms have been selected as focal points 

 around which the groups are discussed. Each term (focal point) heading 

 a group has its subdivisions listed both in the key and in the glossary. 

 Likewise, cross references to the focal points are also contained in the 

 definitions of the final subdivisions. For example, Water Opening lists 

 Crack, Lead, Polynya, and Other as its subdivisions, while the definition 

 for Crack refers to its relation to Water Opening. 



Each term in the glossary is given a classification symbol. This symbol 

 refers to the position of the term in the key. It indicates not only associated 

 terms, but also the relative position of each term with respect to them. 

 The classification symbol is formed by writing in succession the symbols of 

 the applicable subdivisions in the key. For example, Lead is associated 

 with: I. Sea Ice, C. Related Features, 1. Water Opening, and b. Lead. 

 Its symbol, therefore, is (I.C.l.b.). Conversely, the symbol (I.C.Lb.) 

 indicates Sea Ice, Related Features, Water Opening, Lead. Thus, a 

 lead is a water opening, a related feature of sea ice. 



The illustrations are assembled into groups to conform with the divisions 

 of the key so that comparative studies of similar, yet different, ice terms 

 can be made easily. The key lists the figure numbers so that the illustra- 

 tions corresponding to a particular term may be found readily. If a term 

 defined in the glossary is illustrated, the figure numbers are listed following 

 the definition. 



If the glossary is searched for a term made up of two words and the 



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