When one thinks of a barrier island, the smell of salty air and the sound of breaking waves immediately come to mind. Barrier islands are typically thought of as oceanic features, but they can exist along any coast where sediment can vertically accrue, including lakes. In fact, barrier features such as spits and barrier islands can be found nearby in the Great Lakes, where wind, waves and currents combine to create their distinctive landforms.
Both oceanic and lacustrine barrier systems serve as protection for the mainland coast by reducing the effects of wave action and creating crucial backwater environments such as bays and marshes, but they are also highly desired waterfront property and recreational areas. Therefore, it is important to understand of how these systems develop and evolve over time, and to learn about some of the issues that they face, so their natural and social benefits can be preserved.
This study examines the lacustrine barrier systems present in the Great Lakes, looking at three sites in particular, and focuses on the similarities and differences between oceanic systems and lacustrine systems. By understanding these relationships, we can gain an understanding of the processes at work and make better management decisions.
The study begins with a summary of some general characteristics of oceanic barrier systems, including a definition of a barrier system and some common landforms. A discussion of oceanic barrier systems follows, focusing on common sediment sources, typical system controls and favorable conditions for development. A similar discussion on Great Lakes lacustrine barrier systems will follow, including detailed descriptions of two Great Lakes systems, which will illustrate many of the processes discussed earlier.