Last week, reports in multiple media outlets cited a new study that a supervolcano in Yellowstone National Park could explode “sooner than expected” and “destroy all of mankind,” spurring fresh panic online.
The idea of a Yellowstone “supereruption” isn’t new, but it’s still nothing to worry about, said Jeffrey Johnson, a volcanologist and associate professor in geosciences at Boise State University.
“People love to be sensationalist with Yellowstone because when it has erupted in the past, it is huge,” Johnson said. “It’s a prehistoric supereruption. But nothing is out of the ordinary at Yellowstone right now.”
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The study, conducted by Arizona State University graduate students, found that rock crystals from Yellowstone’s last major eruption (630,000 years ago) show “only” decades of influx of new magma as opposed to the millennia of influx that researchers previously thought. That’s a short duration in geologic terms, but still a lengthy span of time in the human experience.
Basically, fresh magma flowing into the Yellowstone magma reservoir created the perfect conditions for an eruption in “the blink of an eye” when you consider how old the earth is.
Though some of last week’s articles offered a bit of clarity on just how “soon” the caldera could erupt, many others left that detail vague. Johnson said the “little notice” that we might have of an eruption is even less significant considering “the likelihood of an eruption anywhere in Idaho — including in Yellowstone — is unlikely in our lifetime.”
He added that it’s much more likely that an Idaho eruption would happen at Craters of the Moon, which has seen volcanic events every 10,000 years or so — though even that isn’t likely to happen while any of us are still around, he emphasized.
“There have been dozens of eruptions in Yellowstone since (the supereruption) 630,000 years ago, and they’re much smaller. These are eruptions we could live through,” Johnson said.
What’s in the realm of reality is an eruption in the Cascade Mountain Range.
“Volcanos in the Cascades will erupt every 100 years. Mount St. Helens erupts on a human time scale,” Johnson said. “On average, Yellowstone erupts every half-million years. That’s 10,000 times less frequently.”
Johnson, who took a group of BSU students to the park just three weeks ago, said Yellowstone is “a very dynamic place,” and it’s not unusual for the area to experience tectonic and volcanic activity. Recently, an ongoing rash of earthquakes in Southeast Idaho has some wondering if the temblors might be a precursor to a massive eruption.
Johnson said the two are hardly related. Though the magma reservoir at the Yellowstone caldera does cause a bulge in the Earth’s crust that contributes to “tectonic strain” — and therefore tectonic activity like earthquakes —those quakes aren’t about to shake loose a stream of lava.
“Yellowstone has effects that are unrelated to eruptions. There’s no relationship between (the caldera’s) magma and what’s happening in Soda Springs,” Johnson said. “The distances between Soda Springs and Yellowstone are huge.”