term is not found under the first word, the order of the words should be 

 reversed. For example, ice shelf is defined under shelf ice. If the meaning 

 is changed by this procedure, both definitions will be given, each in its 

 proper place, as for example, ice river and river ice. Many terms begin 

 with the word "ice" so that this series of terms should be investigated for 

 terms not otherwise easily found. 



When several ice terms have the same meaning, all are listed in the 

 glossary. However, one of these terms has been selected as the preferred 

 term and the definition given under that term. The terms in bold face type 

 in the text, captions, and key are defined in the glossary. In cases of ice 

 terms having more than one meaning, all definitions have been given 

 together with their key classifications. 



In definitions, the abbreviation "cf." has been used to indicate parallel 

 terms, while the word "see" indicates references to a larger division. For 

 example, under crack will be found: Cf. lead. See water opening. 



The following key is an integrated collection of observable ice features, 

 arranged into logical groups for specific purposes. Although the newer 

 knowledge of tomorrow may dictate other arrangements of ice terms, a 

 beginning — good or bad — is needed today. 



XIII 



