Please use this identifier to cite or link to this item:
|Coastal changes, eastern Lake Michigan, 1970-74
|Birkemeier, William A. (William Allen)
|Beach Profile Changes
|Coastal Engineering Research Center (U.S.)
Engineer Research and Development Center (U.S.)
|Miscellaneous report (Coastal Engineering Research Center (U.S.)) ; no. 81-2.
Abstract: Bluff recession and volumetric losses at 17 profile lines along the eastern shore of Lake Michigan were measured monthly from August 1970 to December 1974. Average rate of bluff recession for the period equaled 2.5 meters per year per profile line with an average loss of 4.2 meters per year on the most severely eroded line. Bluff recession tended to increase with lake level but the seasonal peak in recession coincided with the storm period (September to April). Peak recession occurred before ice buildup (between November and December) and just after ice breakup (in the spring, March to April). Lake ice was found to be an effective shore protection agent during the stormiest months of January, February. and March. Till and mixed till bluffs tended to erode less than bluffs composed of sand , but no clear dependence on bluff composition was found. An analysis of the content and median sand size of 519 sediment samples collected from both the foreshore and the backshore during the final 15 months of surveying shows that backshore sediments are generally finer and more uniform than foreshore sediments. High and low concentrations of gravel, usually found on the foreshore, were characteristic of specific profile lines. Deposits of heavy minerals, predominantly magnetite, were usually found on the backshore.
|Approved for Public Release, Distribution is Unlimited
|Appears in Collections: