KREl-ZCRD 



The Hydrographic Office is engaged in a continuing study of 

 ice conditions affecting ship movements in the Arctic Basin. As 

 an essential preface to improving the techniques of ice forecast- 

 ing, it has been necessary to formulate theories concerning the 

 large-scale movements of ice in the Arctic Basin. Application of 

 the techniques of ice potential calculation as described in this 

 report will aid in understanding the causes for the large annual 

 fluctuations in amounts of ice and the persistence of areas of 

 heavy and light concentrations of icco 



j2X^t.^-_^ 



U. B. COCPIRAN 

 Captain, U, S» Navy 

 Hydrographer 



