FOKEITORD 



The formation of sea ice in northern waters often hastens the 

 termination of shipping at Arctic harbors and sites. Retardation of 

 ice growth can reduce or prevent damage to marine structures such as 

 De Long pier at Thule, Greenland. A thorough understanding of pliysi- 

 cal effects which delay ice formation and slow ice growth is required. 

 For these reasons, the experiment performed at Th\ile in 1959 is of 

 considerable interest. 



This report is a study of the effects of air-bubbling on the physi- 

 cal properties of the water adjacent to De Long pier. It attempts to 

 formulate a working hypothesis for explaining the mechanism of the proc- 

 esses which retarded formation and growth of sea ice. 



Conclusions expressed in this report may require revisions as 

 additional data become available. All additional information which 

 might amplify or modify this report will be welcomed by the Hydro- 

 graphic Office. 



Rear Admira. 

 ifydrographe 



