partially destroyed by thermal and mechanical processes (Figs. 41-44, 

 46, 93). 



WEATHERED ICEBERG: (II.A.5.a.)— An iceberg whose irregularity 

 is due to the advanced stage of its destruction, having been well weath- 

 ered and/or overturned. The surface texture of a weathered iceberg 

 resembles the weathered surface of polished white marble. Surfaces 

 which have been under water have a honeycombed structure and a fused 

 glass texture. (Fig. 93.) 



WEIGHT CRACK: (I.C.l.a.)— Hinge crack. 



WINTER ICE: (I.A.3.d.)— Sea ice more than 20 centimeters (8 inches) 

 thick formed and developed in one winter. Winter ice is therefore one 

 year old or less, and is usually less than 12 feet thick. However, if the 

 ice is disturbed by external forces such as wind and current, the thick- 

 ness of the ice cannot be used to infer its age. (Fig. 30.) 



WORKING: (V.A.) — Negotiating ice by boring and slewing. 



YOUNG ICE: (I.A.3.C.) — Newly-formed ice between 5 and 20 centi- 

 meters (2 to 8 inches) thick in the transitional stage of development 

 from ice crust to winter ice. See age (of ice) . (Figs. 28, 29.) 



30 



