OCEANOGRAPHY AND SEA-ICE 



24. The Mackay Tongue moves in summer nearly a 

 yard a day. Such motion obviously prevents bay ice 

 from being" locked to the land, and makes it probable 

 that much of the bay ice is not more than a few seasons 

 old. The crack running northwest from Cape Geology 

 was up to twenty feet wide in places with islands of 

 ice floating within it, which made it possible to cross 





MalnThi/slynwhc Features cfdu Tviackmj QLuuw and- Qranltc Harbour shouting 

 T^unataliker^uruihlkr, Ju- flood Fhor, Foots, Cvms &i Mackay Ice Tonmu.ifi^olun^^est) 



Fig. 24. — Block diagram of Granite Harbor* 

 (By permission of John Murray.) 



with sledges. Some cracks had peculiar deeply serrate 

 edges which indicated where they had been torn apart 

 by the tension. 



Pressure Ridges 



These were very interesting structures due to the 

 pressure either of land-ice or sea-ice upon capes, etc. 

 The writer made a careful study of a set of fifteen 



167 



