96 



POLAR PROBLEMS 



The only known measurements determining the ratio of area of 

 open water to continuous ice cover in the Arctic Pack in summer are 

 the topographical surveys made by Admiral Makarov on the Yermak 

 in 1899 north of Spitsbergen.^ Although two such surveys (Figs. 

 2 and 3), one on August 19 in latitude 80° 44' N. and longitude 9° 5' E. 



Fig. 6 — A lead in the Arctic Pack between Spitsbergen and the pole. Oblique view 

 from the Norge from an altitude of about 500 meters. Note the pressure ridges criss- 

 crossing the ice surface. (Photograph from Lincoln Ellsworth.) 



and another on August 27 in 81° 22' N. and 18° o' E., gave 18 per 

 cent and 28 per cent of water area respectively (they were made on 

 the outskirts of the Arctic Pack), Makarov estimates that in its 

 normal state the ice of the Arctic Pack in summer has 10 per cent 

 of water area. 



' S. Makarov: Yermak vo Idakh (The "Yermak" in the Ice), St. Petersburg, 1901. 



