Figure 53C. Greater ice cover with 

 increasing latitude. Dark patches on 

 ice in foreground consist of sedi- 

 ment. 



Figure 53D. Floe ice extending 

 about 6 feet above water. At 

 72° 14' N navigation difficult. 



Figure 53E. Glacon showing rela- 

 tive amounts of ice submerged and 

 above water. Note also the melting 

 which has occurred at water surface. 



78 



