BEACH PROFILE CHANGES: EAST COAST 

 OF LAKE MICHIGAN, 1970-72 



by 



R.A. Davis, W.G. Fingleton, 

 and P.O. Pritahett 



INTRODUCTION 



1 . Nature and Purpose . 



This study was initiated to collect profile and sediment data that 

 would delineate spatial and temporal variations in beach changes, to 

 correlate these changes to other variables and to particularly identify 

 the effect of long-term lake level changes. This report focuses on the 

 erosion (recession) of the dunes or bluffs (expressed in horizontal feet 

 of landward movement) and examines the relation between this erosion, or 

 the absence of any erosion, and seasonal and annual fluctuations in 

 weather, waves, and lake level during the study period. Throughout this 

 report the term erosion refers to a loss of sediment from the area behind 

 the beach, i.e., the dune, bluff, or foredune terrace. 



2. Previous Studies . 



The processes and sediments of the eastern shore of Lake Michigan 

 have previously been investigated. Characteristics of beach sediments 

 were analyzed by Hough (1935) and Hulsey (1962). Coastal geomorphology, 

 especially longshore bars and troughs, was studied by Evans (1939) and 

 by Saylor and Hands (1970). Few studies are available on the collection 

 and analysis of beach profile data. Powers (1958) and Brater and Seibel 

 (1971) compiled bluff erosion rates for selected sites. A significant 

 correlation between bluff erosion rates and lake levels was the result 

 of a survey using aerial photos and site visits along Lakes Michigan and 

 Huron by Seibel (1972) . Systematic profiling studies and time-series 

 studies of beach processes along Lake Michigan are reported in Davis and 

 Fox (1971), and Fox and Davis (1970b, 1971a). 



3. Study Area . 



The 17 profile sites discussed in this report are located in the 

 State of Michigan along the eastern coast of Lake Michigan between Point 

 Betsie in the north and Lakeside in the south (Fig. 1). The sites, 

 approximately 15 miles apart, were chosen by location and year-round 

 accessibility. However, the sites exhibit a variety of coastal morphology^ 

 composition, and shoreline orientation. 



Each of the 17 sites is shown by a figure which includes: vertical 

 and oblique photos with profile lines indicated; a brief description of 

 the geomorphology; location including the section, tier, range, and 



