Place: 4274 Chamberlin (refreshments will be served)
Speaker: Dave Mickelson, UW Department of Geology
Abstract: The Great Lakes are close to or exceeding record high lake levels. A major concern along many Great Lakes shorelines is what is happening now and what might happen in the future to beaches, and bluffs above the beach. In response to nearshore and beach erosion at the base of the bluff under high lake-level conditions, the lower part of the bluff steepens and becomes more unstable. This instability typically migrates up the bluff face through time and the position of the bluff top eventually recedes, threatening any structures that have been built on the bluff top. I will discuss a qualitative comparison of 2007 and 2018 low-level oblique airphotos of the shoreline from Door County to the Illinois State Line. A primary aim of this study was to evaluate changes on the beach and lower bluff that might predict the likelihood of future bluff-top recession.