Seiches are a natural phenomenon that causes rapid changes in water levels in the Great Lakes, especially Lake Michigan.

Seiches are large, oscillating waves that occur in enclosed bodies of water like the Great Lakes, particularly Lake Michigan. These waves are caused by changes in atmospheric pressure, strong winds, or rapid temperature shifts, leading to sudden shifts in water levels. The phenomenon can cause water levels to rise or fall dramatically in a short period, sometimes flooding coastal areas or exposing previously submerged land. Seiches are a natural occurrence but can be unpredictable, making them a challenge for those living along the Great Lake's shorelines, where they impact ecosystems, infrastructure, and water activities.