Melting of the ice is such that the ice sheets between the ridges and 

 between the shore and the first ridge melt first. This presents a series 

 of two or three ice ridges with open water between them. However, the 

 ridges are still an effective barrier to wave and current energy. Breakup 

 of the ridges, their subsequent removal, and melting are generally caused 

 by storms. As a result, the beach may go from a zero-energy situation to 

 a high-energy condition in a matter of a few days. 



IV. METHOD 



1 . Profiling Method. 



Profiling techniques are the same as those used for data reported by 

 Davis, Fingleton, and Pritchett (1975); the following description is 

 adopted from that report. The technique for measuring beach profiles is 

 essentially that described by Emery (1961) . The only equipment used is a 

 pair of wooden stakes, 5 feet long and graduated at 0.1-foot intervals. 

 The method requires at least two persons although it is desirable to have 

 a third to record the data. 



The survey was started at a bench mark using a metal pipe or wooden 

 stake. The height of the stake above ground level was noted to recognize 

 any accumulation or erosion to the surface adjacent to the stake. The 

 direction of the profile (perpendicular to the beach) was visually approxi- 

 mated. Horizontal distances were measured with a 5-foot stake, and topo- 

 graphic changes less than 5 feet in horizontal distance were recorded to 

 the nearest foot. Vertical changes were determined by lining up the hori- 

 zon with the top ,of the lakeward stake and noting the difference to the 

 nearest 0.05 foot on the landward stake. Horizontal changes were refer- 

 enced to the bench mark; vertical measurements were referenced to the lake 

 level at the time of the first survey which was 579.4 feet, International 

 Great Lakes Datum (IGLD) . Measurements were made by a hand level in case 

 of fog or ice ridges which could prohibit sighting of the horizon. 



2 . Profiling Format and Dates Visited . 



Each of 17 beach sites was visited once every 4 weeks, and the routine 

 for data collection remained fairly constant. The basic format was as 

 follows : 



(a) Location of the monument and determination of the need 

 of an auxiliary stake if the permanent stake was in danger of 

 removal by erosion. 



(b) Profiling the beach to the plunge step, if possible, 

 using the technique by Emery (1961). During late fall storms 

 it was sometimes impossible to profile to the desired terminus. 



(c) As each profile was surveyed, notations were made of 

 topographic and sedimentologic features on the profile. These 

 included small wave-cut features, ridge and runnel development, 



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