TABLE 56. TRANSPARENCIES OF ICE IN PER CENTS 



These measurements showed an almost 100 per cent transparency of dry ropak ice which, 

 thus both in its composition and transparency approached pure, fresh water ice. As Trofimov 

 himself indicates, however, the results cannot be considered especially significant due to the 

 difficulty of observation. 



During the 1935 Sadko expedition, V. Berezkin lowered a photometer into an ice hole about 

 30 cm in diameter which was later filled with brash ice. On 12 August at 81° 10' north, and 

 26° 29' east under sunny, cloudless skies and with a snow cover of 3 to 5 cm, (the average of four 

 observations) illumination at a depth of 5 m was about 2 per cent of the surface illumination. Ice 

 was glass-like and transparent and with a great number of air bubbles 5 to 6 mm in diameter. 



Nazarov gives the following of his observations conducted in April 1936 4 km from Uedineniie 

 Island at a depth of 13 m, through fast ice 120 cm thick and covered by 20 to 30 cm of snow. 

 Observations were conducted in a closed tent through a special hole. The bottom was well illum- 

 inated constantly. Under clear skies, the bottom shone, which Nazarov explains as the reflection 

 of a large amount of light. It was easy to distinguish separate stones on the bottom, and swimming 

 fish and sea animals in the water. 



At my request, in March 1941, Bardovskii conducted observations of under-ice illumination 

 with the aid of a secchi disc in Matochkinshar Strait. The results of these observations are 

 presented in table 57. 



TABLE 57. THE TRANSPARENCY ACCORDING TO THE SECCHI DISC, 

 UNDER THE ICE OF MATOCHKINSHAR STRAIT 



Average 



16 



114 



23 



30 



Average of 



10 observations 



in June 



34 



132 



13 



20 



179 



