This website will focus on a research expedition undertaken in the summer of 2013 which focused on the Duluth Bay Barrier. The project was a collaboration between University of Wisconsin: Eau Claire (UWEC) students David Simenson and Ryan Alger, and UWEC professor Harry Jol. To learn more about our use of ground penetrating radar on this unique and import landform, start with our abstract below!
The twin port cities of Duluth, MN and Superior, WI on the southwest side of Lake Superior are encapsulated by the Duluth Bay Barrier. The bay barrier is composed of two spits, Minnesota Point and Wisconsin Point which are divided by the natural channel of the St. Louis River outlet. Studying the internal stratigraphy, through ground penetrating radar (GPR), helped show how erosion, littoral drift, human activity, and lake level change have affected the morphology of the bay barrier. Several cross barrier and parallel transects were collected on both spits. The pulseEKKO 100 GPR system was used for data collection with 50, 100, 200 MHz antennae. Data was processed, plotted, and analyzed through pulseEKKO software. Radar stratigraphic analysis showed multiple reflection patterns revealing three distinct sediment packages indicated by unconformities and changes in geometric characteristics. All containing Sigmoidal features dipping lake ward, suggesting there is evidence that the bay barrier system is a progradational feature fed by littoral drift from the southeast.
Collecting data on Minnesota Point
Investigating the Subsurface of the Duluth Bay Barrier 