direct support of surface operations in these -waters. Also used as 

 material for this study were ship and shore observations of ice condi- 

 tions taken in recent years, and some historical data contained in 

 reports of the many exploratory voyages in these waters during this 

 and the past century,, 



This information should serve as a useful guide and reference in 

 determining feasibility of emergency landings on ice, and the planning 

 and execution of operations in these waters, particularly when modified 

 to reflect the deviations from normal of factors controlling the growth, 

 distribution, and behavior of sea ice. 



Minor corrections have been made in the reprint of this report, 

 formerly identified as H.O. Misc. 15891 and printed in 1954. 



vi 



