1600 



1500 



"° ili#i,,,IWi**W4./iffl 



5.0 — [ 



mjmmm 





^ 



_/_ 



z 



—J- 



500 



FIG. 22 NOISE LEVEL CHART 



1600 



HOURS -24 FEB. 1961 



UPPER- DEEP HYD 



LOWER -SHALLOW HYD. 



