First longitudinal mode 

 ( period ,9hr 



Portage 



Ludington 



Pentwater 



Muskegon 

 Holland 



Second longitudinal mode 

 { period, 5. 3 hr 



Third longitudinal 

 mode 

 (period,3.5 t)r) 



Muskegon 

 Holland 



antinode 



Relative Seiche Height of Water 



( normalized by level at 

 the southern tip of 

 Lake Michigan ) 



Figure 3. Three predicted longitudinal modes of oscillation of Lake 

 Michigan (modified from Mortimer, 1965). 



