CONTENTS 



Page 



Introduction 1 



General features of Lake Michigan 



Current -generating agents and modifying factors , 



Wind 



Density 



Morphology 



Coriolis force 2 



Hydraulic currents 2 



Types of drift units 2 



Drift bottles 2 



Plastic tubes 5 



Drift envelopes 5 



Releases and recoveries 5 



Central and southern Lake Michigan, 1954 5 



Central and northern Lake Michigan, 1955 5 



Time and localities of recovery 5 



Surface currents in Lake Michigan, 1954 and 1955 8 



Central and southern Lake Michigan, 1954 8 



South Haven -Waukegan transect 8 



Grand Haven -Milwaukee transect 9 



Ludington -Manitowoc tr<lnsect 9 



Rate of drift 16 



General characteristics of surface-water movements 16 



Central and northern Lake Michigan, 1955 16 



Grand Haven -Manitowoc -Stiuge(xi Bay transects 16 



Ludington -Manitowoc transect 16 



Frankfort -Sturgeon Bay transect 24 



Charlevoix -Manistique transect 27 



Rate of drift 27 



General characteristics 27 



Summary 33 



Literature cited 33 



Appendix 34 



iii 



