Lake Superior Could Flood Americas

The sheer scale of Lake Superior is difficult to comprehend. While it is the largest of the Great (Review) Lakes by surface area, its true immensity lies in its depth and volume. The lake contains an astonishing 2,900 cubic miles of water, representing 10% of all the planet's available surface freshwater. This volume is so vast that if its contents were somehow spread evenly across the combined landmass of North and South America, it would submerge both continents under a foot of water.

This incredible basin is a relic of the last Ice Age. Over thousands of years, the colossal weight and grinding force of the Laurentide Ice Sheet scoured and deepened a massive geological rift in the North American continent. When the glaciers finally retreated about 10,000 years ago, their meltwater filled this newly carved chasm, creating the lake we see today. Because it is fed by hundreds of smaller rivers rather than a few major ones, its water retention time is incredibly long. This slow-flushing system means that if the lake were ever drained, it would take a staggering 191 years for those same sources to fill it back up.