Superior 2007 Field Excursion

Coastal Development

Large Lakes Observatory

Canal Park

Marine Museum

Coastal Development

Dr. Jol's Site

After our stop at the University of Minnesota – Duluth, we made our way down to a barrier island where Canal Park is located. Before touring Canal Park and the Army Corps of Engineers Museum, we walked along the beach to look at some coastal processes and their effects on development. The most important feature along the beach was the coastal dunes. These dunes were formed by the process of longshore drift. Longshore drift occurs in large lakes as a result of currents transporting sediment along the shoreline. As the current moves, lighter sediments are moved more easily and thus beaches are formed. The results of longshore drift can also be seen along the north shore of Lake Superior as there is mostly larger rock and very little sand. This is because the longshore drift has carried the sand to its current location, Canal Park.

Because this barrier island has formed, development must be carefully planned out. Along the beach that we walked, there were numerous places where development has severely damaged the fragile dune system. In many of these places, blowouts are the main problem. A blowout occurs when proper precautions are not taken when building or allowing people to explore the area. As people cross the dunes, their paths cut down into the dune which allows the wind to blow through that channel. The wind then erodes the dune out even more in that area and eventually the dune can become completely bisected. This also happens when people build on the dunes or behind the dunes. Many times, people will build on one side of the dune but soon realize that they cannot see the lake from the lower story of their house, so they decide to remove the section of the dune that there house is on which in turn creates a blowout. There are, however, a few precautions that can be taken to prevent these costly blowouts. The most common way to prevent tourism from causing a blowout is build a boardwalk over the dune so that the walking traffic doesn’t cut into the dune. To prevent blowouts due to development, besides not removing portions of the dune, there are two methods that work. One is to introduce vegetation so that the roots help hold the sand in place. Another method is to use a fence. A fence will slow down the wind allowing the blowing sand to be deposited. Eventually the sand builds up creating a dune.