GEOL 118 Lecture Notes - Lecture 33: Silt, Total Variation, Lake Chicago

• School: University of Illinois
• Department: Geology
• Course: GEOL 118
• Professor: Thomas Johnson

Document Summary

Geol 118 - lecture 33 - coastal erosion iii. Lake plain - extends for ~50 km from in border to wilmette. Located on silt and mud that formed from glacial lake chicago. Glacial till cliffs - on moralness composed of till deposited directly by glacial ice. Land use = developed with expensive homes. Beach ridges - ~15 km strip from wi border to waukegan, il mostly within il beach. Small dunes formed over past several thousand years due to build up of beach drift. Lake levels are more variable than sea level. Depend on regional precipitation and human controls. From 1920 to 2000 total variation in level of lake michigan is ~1. 5 m. Historic high in 1986, historic low in 1964. In natural state, much of illinois shoreline was highly vulnerable to wave erosion. Now most of shore is protected but erosion remains problem, especially during high lake water levels.