It’s the stuff of movies. Massive volcanic eruption, ash clouds turning the sun and moon black or red. Weather patterns altered. Artificial winter.
It is also the stuff of historical record. Three times in observable geologic history, Yellowstone’s massive volcano has erupted. The latest was a little over half a million years ago, say scientists. When it blew, millions of tons of rock were evaporated, turned to ash and projected 25 miles into the atmosphere. Massive earthquakes ripped apart geological formations. The sun was blocked out. Regional temperatures dropped, and ice and snow froze large chunks of the continent.

