Velocity Distribution at Two Sites within the Southern Basin of Lake Michigan

摘要

The report summarizes data on velocity and suspended sediment characteristicsnear Wilmette Harbor on the southwestern shore of Lake Michigan. The report also includes analyses of velocity structure at a Lake Michigan site where 8,000-year-old tree stumps have been discovered and showed that the water normally moved in a southeasterly direction, following the shoreline. This coincides with the existence of a classical longshore current pattern. Much greater fluctuations were found at the nearshore station than at the farshore station. Suspended sediment concentrations did not show much variation over the three-day data collection period. The bed materials at the site ranged from fine to very fine sand sizes. Data from the tree stump site, collected during a four-week period, showed at least three peaks in water temperature. The average velocity was about 2.6 centimeters per second, and the current rotated by about 360 deg within a period of four to five days.