News / Utah / 

Study Finds Yellowstone's Volcanoes More Powerful Than First Thought

Study Finds Yellowstone's Volcanoes More Powerful Than First Thought

Estimated read time: 2-3 minutes

This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.

John Hollenhorst Reporting The volcanic power churning beneath Yellowstone National Park between eruptions is much greater than scientists thought. A new study reveals a fascinating new picture of one of history's biggest and potentially most dangerous volcanoes.

Yellowstone may be asleep, now. But it's a slumbering giant. When we visited Robert Smith at the University of Utah. He was looking at the latest snoring, a swarm of hundreds of small earthquakes.

Dr. Robert Smith, University of Utah: "It tells you that Yellowstone is alive. Earthquakes are happening all the time."

Thirty times in the last two million years, Yellowstone erupted, bigger than Mt. St Helens. Three times it erupted cataclysmically, leaving behind a gigantic crater or caldera. Scientists have been recording Yellowstone's shakes and groans and its changing shape. Now they've analyzed the data.

Study Finds Yellowstone's Volcanoes More Powerful Than First Thought

Christine Puskas, University of Utah: "I was rather surprised at how large it was, the scale of the deformation."

They found what they call "huffing and puffing".

Dr. Robert Smith: "Then it went down, then went up, went back down, and now it's really going up again. It was very surprising. I thought we'd just have kind of a continuous uplift and a continuous stretching of the caldera."

The caldera, 30 to 40 miles across, rose more than three feet before falling and rising again, a signal of tremendous energy.

Dr. Robert Smith: "And the whole thing is going up and down together. Which means the plumbing is connected over a very large region."

Using the seismic equivalent of a CAT scan, they produced the first image ever of a hot-spot plume. It's a huge column of superheated rock reaching up 400 miles from the mantle of the earth. Over the millennia, it probably caused major volcanic eruptions in Idaho and Wyoming, but it's relation to Yellowstone at rest is uncertain.

Christine Puskas: "It's not clearly, the huffing and puffing, right now the mechanism is not clearly known."

So what does it mean in terms of predicting future eruptions and earthquakes? Well, it's opened the door to more science to try to answer that question.

Dr. Robert Smith: "We all think volcanism will continue. But what scale and what timing, we don't know."

The good news is that Yellowstone seems to sleep many thousands of years. There's no particular reason to think a wake-up call is coming anytime soon.

The last cataclysmic eruption at Yellowstone was more than 600,000 years ago. It was so big it would have affected the climate world-wide. If it happened today, it would bury most of the lower 48 states under volcanic ash.

Most recent Utah stories

Related topics



Catch up on the top news and features from, sent weekly.
By subscribing, you acknowledge and agree to's Terms of Use and Privacy Policy.

KSL Weather Forecast