Bluff 



Erosion 



1970-72 



(feet) 



Beach 



Width 



1970-72 



(feet) 



ice on 

 Beach 



Breather 

 Height 

 1972 

 (feet) 



50 



25 



50 



25 



0.5 







Wind > 20 mph 20 

 1960-70 

 (days) 



Water 

 Level 

 1971 

 (feet) 



Figure 27, 



10 



580 



579 



578 



Water 580 

 Level 



(feet) 



578 



Yes Yes Yes No No No No No No No No No 



Average for three or fewer sites 



Jon Feb Mar Apr May June July Aug Sept Oct Nov 

 Months 



Dec 



Mean monthly values of Lake Michigan environmental variables 

 (wind data from Seibel, 1972]. 



56 



