Key to plots ; All data are relative to a vertical datum of 176.88 meters 

 (IGLO) or TTO? meters above LWD. This datum, which Is also the shoreline 

 elevation, represents the average lake level during the period, October 1973 

 to December 1974. To illustrate- the Influence of changing lake levels, the 

 distance to the contour equal to the average monthly lake level was computed 

 and plotted as the waterline. Solid triangles represent periods when the 

 beach was narrower or equal to the beach defined by the shoreline. Open 

 triangles indicate wider beaches. The line marked "bluff" indicates the 

 cumulative change in position of an elevation contour (given in parentheses) 

 which represents the bluff crest during the first survey. Plotted positions 

 of the shoreline, bluff line, and lake level are relative to the location of 

 the shoreline during the first survey of each line. Beach volumes were 

 computed above datum and below the 1.25-meter contour (or 177.13 meters IGLD). 

 Bluff volumes were computed above 1.25 meters and below 13.25 meters. Volumes 

 plotted represent cumulative changes. Because of ice cover, data collected 

 between January and March 1974 have been omitted. 



-= 10 



> -30 



-10 



Oct. Nov. Dec. Jon. Feb. Mar. Apr. May June July Aug- Sept. Oct. Nov. Dec. 



Profile line 1 



Figure A-2. Plots of cumulative change to the shoreline, waterline, bluff 

 line, beach volume, and bluff volume for the 17 profile lines, 

 October 1973 to December 1974. 



45 



