CONTENTS 



Page 



CONVERSION FACTORS, U.S. CUSTOMARY TO METRIC (SI) 7 



SYMBOLS AND DEFINITIONS 8 



I INTRODUCTION 11 



II LAKE AND INLET HYDRAULICS 11 



1. Great Lakes and Inlet-Bay System Hydraulics 11 



2. Prediction of Inlet Velocities 16 



III THE FIELD DATA COLLECTION PROGRAM 23 



1. Field Measurements 23 



2. Equipment 34 



3. Data Reduction and Analysis Techniques 34 



IV RESULTS 35 



1. Seiching of the Great Lakes 35 



2. Predicted Inlet-Bay Response to Monochromatic Long 



Wa\^e Forcing 39 



3. Observed Lake Level Fluctuations, Bay Response, and 



Inlet Velocities 47 



V INLET DESIGN 56 



1. New Inlet Channel 56 



2. Inlet Channel Modification 61 



VI SUMMARY AND CONCLUSIONS . 63 



LITERATURE CITED 68 



TABLES 



1 Summary of field measurements 32 



2 Inlet and bay geometric measurements 33 



3 Modes of oscillation of the Great Lakes 38 



4 Influence of Manning's n on inlet-bay response at Pentwater . 39 



5 Predicted periods of maximum wave amplification and maximum 



inlet velocities 43 



6 Predicted Duluth-Superior maximum inlet water velocities for 



a forcing wave of 1 hour (a^ = 3 centimeters) 47 



7 Numerical Model Prediction of Pentwater response to Lake 



Michigan modes of oscillation 48 



4 



