20.0 3.0 1.4 1.0 



Period ( hr) 

 0.7 0.5 



0.4 



0.3 



1.44 Wove Period (hr) 



1.0 



l\ 



Lake Michigan 

 Penfwater Lake 





<\ 



0.38 0.73 



.08 L43 1.78 2.13 2.48 2.84 3.19 3.54 

 Frequency (c/hr) 



r 0.1 77 



Time,4hr 

 I 1 



Figure 21. Sample Pentwater and Lake Michigan water levels and spectra. 



51 



