“The Great Lakes lack the predictable regularity of tides; a combination of factors including winds, temperature and current depth influence currents. Combined, these factors cause a complex, spiraling water flow, producing a type of interior (rather than surface) waves called inertial waves.

 

The researchers hypothesize that the inertial waves are the primary mechanism governing the movement and dispersion of particles. ‘You can get currents as strong as a half-meter per second in the middle of Lake Michigan,’ Cary Troy of Purdue’s School of Civil Engineering said prior to the study. ‘The effect is strongest in the middle of each of the Great Lakes, so that’s why we are doing the research there.’

 

‘The goal is to do dye-release experiments and to track the dye patch over time to see where it diffuses and where it moves and to relate that to the information we have about the lake currents and waves,’ Troy said. ‘One obvious application is for something like an oil spill or any sort of contaminant spill in the Great Lakes. If you have a spill, you need to predict where it’s going to go and how quickly it’s going to dissipate.'”