ANCIENT FLASH FLOODING ON A GRAND SCALE
During the last ice age, between 15,000 and 13,000 years ago, cataclysmic floods known as the Missoula Floods created an onslaught of water like nothing encountered before. In what is now the northwestern United States, sudden ruptures of the ice dams caused an incredible amount of water to flow down the Columbia River Gorge and inundate much of what is now Washington State and Oregon.
The amount of water estimated to have poured through the broken ice dams was calculated at 10 cubic kilometers per hour. For comparison, that is 13 times the amount of water flowing in the Amazon River each hour. It was also estimated that the flow speed of the flood was around 80 miles per hour. This cycle continued many times over a 2,000-year period. The time it took for the dam to break, refreeze and restructure itself was estimated at nearly 55 years.
So, the next time you encounter a flash flood during your travels, consider yourself truly lucky that you don’t have to face the unfathomable power and destruction of the Missoula Floods!