The 13th Floor

What Would Happen if Yellowstone’s “Supervolcano” Erupted Tomorrow?

Bear in mind, we’re just imagining a hypothetical scenario, based on scientific evidence and other available data, so don’t start panicking… not yet, anyway.

Seismologists at the U.S. Geological Survey (USGS) have been monitoring a major increase in seismic activity at Yellowstone National Park in northern Wyoming — within the intersection of the Yellowstone Calderas, or “hotspots” — but better known in the media by a more ominous nickname: “The Yellowstone Supervolcano.”

Image Credit: Michael Ver Sprill

This so-called “swarm” of quake activity is the real deal, though, and includes more than 200 mini-quakes over just the past few weeks; according to Newsweek, the USGS reported a major swarm last summer as well — totaling around 2400 tremors. It’s actually rather common to the region.

“Yellowstone is just a very swarmy place,” says Michael Poland, head of the USGS’s Yellowstone Volcano Observatory, in the same Newsweek story, noting that the quakes are subsiding again… for now. “These things wax and wane, so it’s a bit difficult to say that it’s ending,” Poland admits.

According to the USGS, the cause of a quake “swarm” can’t be traced to a single source, which makes them hard to measure and track with perfect precision… but the most recent swarms are known to have occurred in 2004, 2009, 2010 and 2017. However, let’s consider the last major eruption of the Yellowstone Supervolcano — which is estimated to have taken place around 640,000 years ago: the “Lava Creek eruption,” which resulted in the ejection of roughly 240 cubic miles of volcanic material into the atmosphere. (By comparison, the catastrophic eruption of Mount St. Helens in 1980 ejected only 0.7 cubic miles.)

Image Credit: iStock/mlharing

Another possibility, perhaps even more devastating than a lava eruption, is a hydrothermal explosion — a “mega-geyser,” so to speak — when a powerful earthquake displaces millions of gallons of water in an instant. One such event created Mary Bay, after continuous tsunami waves from Yellowstone Lake ripped the top from a large geothermal network — triggering an atomic bomb-sized explosion.

But despite these nightmarish imaginings, seismic experts are not concerned at all. In fact, there is no evidence pointing to a major eruption of any kind in the near future.

“This is Yellowstone being Yellowstone,” Poland says.