An Assessment Of The Environmental Effects Of Dredged Material Disposal In Lake Superior Dynamics Of Mixing And Dispersal PDF Download

The two areas selected for study, the north coast of the Keweenaw Peninsula and the western embayment of Lake Superior near Duluth-Superior, differ greatly in their mixing and dispersal characteristics. Nearshore turbidity along the Keweenaw Peninsula contrasts to relatively large turbid eddies off of Duluth-Superior. Turbidity along the north coast of the Keweenaw Peninsula is frequently confined to an even narrower coastal area later in the summer which is under the influence of the strong, well-defined coastal current. Flowing northeast along the north shore of the Keweenaw Peninsula during the summer months, the Keweenaw current follows the coast at speeds ranging from 40 to 90 cm/sec. (Yeske, 1973). Although sometimes narrower, the Keweenaw current normally ranges in width from five to ten kilometers. The surface thermal structure of this current indicates the presence of eddies, meanders, and counter-currents (Ragotzkie, 1966; Smith, 1972). Other studies of the Keweenaw Current structure include Ragotzkie and Bratnik (1965), Smith and Ragotzkie (1970) and Yeske, et. al. (1972).