Lakshika Girihagama, Mathew Wells, Bryan Flood, Reza Valipour, Patricia Semcesen, Scott Parker

The Sweepstakes in Fathom Five National Marine Park is one of Ontarios more iconic shipwrecks. Continued exposure to water currents has directly and indirectly affected the integrity of the wreck and resulted in management interventions including efforts to stabilize the wreck and control vessel activity. An extensive series of field measurements were made during the peak tourist season in the summer of 2015 with the aim of differentiating between natural hydrological processes present at this site versus human-derived water movements. There is a high-degree of natural current variability from processes as diverse as wind-induced surface gravity waves, internal gravity waves, and diurnal flows due to differential heating. Our results show that circulation driven by internal gravity waves derived from upwelling is insignificant. While vessel induced currents were detectable at the shipwreck, they were no larger than the normal summer variability. There is evidence of scour around the shipwreck which likely comes from large wave events from winter storms. Monthly climatological significant wave heights for Lake Huron suggest that typical winter storms contain far higher wave heights than anything observed in summer 2015 and could be responsible for the sediment scouring around the shipwreck.