In the post-Cold War world, where the threat of global thermonuclear war has faded somewhat, among the scenarios for the end of the world that include asteroid strikes, global warming, and the zombie apocalypse, is the Yellowstone supervolcano.
Yellowstone National Park contains a vast reservoir of liquid magma, called a “hot spot,” which provides the heat that causes the picturesque geysers that visitors find to be so enchanting. However, the magma could also cause a super eruption that would be a continent wide and perhaps even a planetary catastrophe.
I09 recently interviewed USGS geologist Jake Lowenstern, scientist-in-charge of the Yellowstone Volcano Observatory, and asked what would happen if the supervolcano were to erupt, just as it did last 640,000 years ago.
“A super eruption, like all volcanic eruptions, begins with an earthquake. A lot of earthquakes have to occur to break the rocks and allow magma to get to the surface,” Lowenstern said, adding that we’d need some big ones in the weeks or months leading up to the eruption. That means there would be many warning signs before it happened — this eruption wouldn’t come out of nowhere.
“Next, enormous vents or fissures in the Earth would break open near the caldera, perhaps in a ring around it or maybe as far as 10 kilometers away. Lava and superheated gasses would shoot out of these vents very rapidly, draining the magma reservoir beneath the caldera. As the the magma quickly drained, the caldera would begin to crumble. Eventually, it would collapse in an oval-shaped sinkhole that might be roughly 50 miles long by 30 miles wide.”
The lava field would cover the park, about a 30- to 40-mile radius. But the real damage would be caused by the ash and pumice that would be shot into the air and spread about, killing farmland, and clogging waterways. Lowenstern believes that the damage would occur in the Midwest and Mississippi River regions. Others believe that the damage would be spread out across the continent, depositing several inches of ash. Air travel would be impossible over much of North America for an unknown period of time. Global cooling would occur for several years.
So is the Yellowstone supervolcano due to erupt at any time, killing millions and perhaps ending American civilization? The National Science Foundation thinks not, thanks to recent research. Ilya Bindeman, an associate professor of geological sciences at the University of Oregon, has concluded that the Yellowstone supervolcano is not likely to build up enough pressure to let go for another 1 million to 2 million years. So we can scratch that off of the list of disasters that can cause civilization-ending events.