VIII. MISCELLANEOUS OBSERVATIONS 



A. Transparency and Water Color 



Table 2 summarizes transparency and water color data obtained on 

 DEEP FREEZE 60. Transparency estimates were obtained by averaging 

 the depths in meters at which the white and black Secchi discs (about 

 30 cm. in diameter) disappeared from sight on lowering and reappeared 

 on raising. Aside from the limitations attendent with such observations, 

 it is felt that they have some gross relative value in describing sea 

 water transparency. Several estimates of water color were made by 

 visual comparison with a modified blue-green-yellow Porel scale. Deter- 

 minations were made in percent yellow, but are listed in the table by 

 actual color. 



In the deeper portion of the Western Ross Sea, transparencies 

 averaged Ik meters for the white disc and 7 for the black; water color 

 ranged from blue to deep blue. In the shallower water of McMurdo Sound 

 and Ross Ice Shelf, transparencies were considerably less, averaging 

 about 7 meters for the white disc. These low values and prevalence of 

 greenish blue water color are attributed to the summer plankton bloom. 



Observations taken in Thurston Peninsula area during late February 

 resulted in values for the white disc of 15 to 17 meters. Water color 

 was described as deep blue. 



TABLE 2. TRANSPARENCY AND WATER COLOR MEASUREMENTS 



Date 



Position 



Transparency 



Water Color 







(Meters ) 





Eastern Balleny Basin, Ross Sea Area 



White 

 Ik 



Black 

 7 





13 Jan i960 



68«00'S, 179*55'E 



Blue 



Ik Jan i960 



69»03'S, 179°06'E 



17 



8 



Blue 



Ik Jan i960 



70°02 , S, 179'10'E 



13 



7 



Blue 



15 Jan i960 



71'13'S, 179*10'E 



19 



6 



Blue 



16 Jan i960 



72"00»S, 179°10'E 



19 



8 



Deep Blue 



West of Scott 



Island, Ross Sea Area 









9 Dee 1959 



6k*55'S, 177 •01* E 



8 







3 Jan i960 



65 # 58'S, 176*20'E 



13 







k Jan i960 



66°19'S, 177°06'E 



Ik 







1* Jan i960 



66°25'S, 177°22'E 



ll* 







k Jan i960 



66 e U2'S, ITS'OO'E 



Ik 







k Jan i960 



67 e O0 , S, 178°l*VE 



Ik 







k Jan i960 



67°21'S, 179*33*E 



11 







k Jan i960 



67°39'S, 178°57'E 



13 







k Jan i960 



67°5^'S, 178«2VE 



15 







5 Jan i960 



68*08*3, 177 , 56'E 



16 







52 



