Yellowstone Supervolcano Isn't About to Erupt: But Here's What Happens When It Does

Not a supereruption: Grand Prismatic Spring, with its colored bacteria and microbial mats, in Yellowstone National Park, Wyoming. Scientists say a recent New York Times article about the changes in magma beneath Yellowstone has been misinterpreted. Jim Urquhart/Reuters

The supervolcano beneath Yellowstone is not about to erupt.

That's right. Take a deep breath: in, out. Good.

Hyperbolic headlines of an eruption, which scientists have dismissed as sensationalized, have stoked something of a panic this week. Contrary to their sense of alarm, the odds of a supereruption beneath Yellowstone park in the next few thousand years are "exceedingly low." As Snopes details, these stories seem to have misinterpreted a New York Times article based on the work of Hannah Shamloo of Arizona State University, and to have raised the specter that the volcano under Yellowstone could, at some point soon, undergo a "supereruption."

Rather than predicting a perilous blanket of ash, Shamloo's work provides evidence that the changes in the magma beneath Yellowstone that led to the last such supereruption happened on a shorter geological timescale than previously thought. As Snopes points out, many outlets seemed to have zeroed in on lines like this from the Times story: "Scientists are just now starting to realize that the conditions that lead to supereruptions might emerge within a human lifetime." That does not mean a supereruption is going to happen within a human lifetime.

This misunderstanding led to end-times headlines like: "Yellowstone supervolcano may blow sooner than thought—and could wipe out life on the planet."

As Newsweek reported yesterday, the findings presented by Shamloo do not allow scientists to predict when the next eruption will take place. But they can serve as a kind of early warning system.

Mike Poland, director of Yellowstone Volcano Observatory, which monitors the volcano under the national park, previously told Newsweek that "Even if large eruptions are preceded by only decades of unrest, this is still something we are positioned to detect well in advance. Yellowstone is one of the best-monitored volcanoes in the world, with a host of seismic, deformation, thermal and geochemical sensors and satellite data sets always looking for changes."

And while the word supereruption does not exactly inspire calm, the panic around Yellowstone raises the question, What exactly are people so afraid of?

According to the United States Geological Survey (USGS), three of these supereruptions—known as caldera- or crater-forming eruptions—have occurred in the last 2.1 million years. The most recent of these was 631,000 years ago.

The word caldera refers to the huge craters that form when the massive flows of magma from these events cause the ground to collapse and swallow the mountains above.

In the words of the USGS: "If another large caldera-forming eruption were to occur at Yellowstone, its effects would be worldwide. Thick ash deposits would bury vast areas of the United States, and injection of huge volumes of volcanic gases into the atmosphere could drastically affect global climate. Fortunately, the Yellowstone volcanic system shows no signs that it is headed toward such an eruption. The probability of a large caldera-forming eruption within the next few thousand years is exceedingly low."

Now, feel free to redirect your anxieties elsewhere in the news cycle.