The creationist ship is foundering.
In parts one and two we examined the young-earth creationist claim that the Great Unconformity in Grand Canyon was carved by the onset of Noah’s Flood. Today we’ll take this a step further, and explain what we would expect to see if the creationist story were true.
It turns out that geologists have a fair idea of what gigantic floods do to the surface of the earth. We can look at a couple places in the world, particularly in eastern Washington State, and see evidence for giant—though not worldwide—movements of water.
The Missoula Floods of eastern Washington were a series of vast deluges that occurred between about thirteen and fifteen thousand years ago. Perhaps as many as forty separate times, an ice dam holding back an estimated five hundred trillion gallons of glacial meltwater breached suddenly. (How much water is that? Think Lake Erie. Then multiply by four.) This water came from the melting ice sheet that once covered all of Canada. The resulting waters scoured the land from east to west across Washington, before finding the Columbia River Gorge and spending themselves into the Pacific.
Along the way, these Missoula Floods left distinct marks: