LEGEND 



— o 1959 Measurement 

 •- D 1965 Measurement 



Nor folk , Virg inio 



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olo , 



Cana 



Zone 



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v( 







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 1 



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5 10 15 20 



5 10 15 20 



Maximum Pitting Rate (Mils Per Year) 



Figure 8. Pitting profile. (From Brouillette and Hanna, I966) 



18 



