Yellowstone Supervolcano More Super
Now thought to be 400 miles wide below ground
Superheated pools of water give hints of what’s bubbling below Yellowstone National Park. Photo by National Park Service.
There’s more to Yellowstone than fabulous views, amazing animals, hot springs and Old Faithful. Yellowstone is a supervolcano that, when it next blows, will bring an end to the United States as we know it.
It’s happened before. At its last major eruption, 640,000 years ago, the Yellowstone volcano deposited a thick layer of ash all across the continent. It erupted another 640,000 years or so before that, and again roughly 640,000 earlier. That means it could be ready to blow again – tomorrow, next week or any time in the next 50,000 years or so.
While the next eruption of Yellowstone is probably not worth adding to your list of things to worry about, the latest news from this supervolcano is that it’s bigger – a lot bigger – than anyone previously imagined.
The plume of molten rock that’s roiling underground waiting to erupt was thought to be about 37 miles wide by 25 miles long. That’s already a lot of molten rock waiting to explode. But a new study, shortly to be published in the Geophysical Research Letters journal, concludes that the plume is, in fact, close to 400 miles wide, stretching from the National Park in Wyoming, through Idaho, and deep into Montana. That’s vast.
How big an eruption to expect
One of the biggest volcanic eruptions in recent Earth history was at Krakatoa in 1883. It was heard thousands of miles away and sent clouds of ash all around the planet, changing the weather worldwide and creating green sunsets for the next three years.
Krakatoa sent about 11 cubic miles of ash and rock into the air. The last major eruption of Yellowstone, by comparison, was unimaginably bigger, sending 240 cubic miles of hot ash and rock into the air.
There have also been smaller eruptions at Yellowstone – still huge, but relatively “smaller”. The last of those was 70,000 years ago.
Over the last six years, the supervolcano has been taking deep “breaths,” causing miles of ground to rise about 10 inches in many places. “It’s an extraordinary uplift, because it covers such a large area and the rates are so high,” said Bob Smith of the University of Utah, who’s an expert on the Yellowstone volcano.
Initially, Smith and his colleagues thought that this uplift could signify an eruption of some kind. The mountainside at Mount St. Helens swelled dramatically shortly before the eruption there in 1980. But other volcanic regions, including Yellowstone, have risen and fallen without an explosion.
There are also roughly 3,000 mini-earthquakes at Yellowstone each year as the ground adjusts to the plume below.
What to expect
Very simply, the supervolcano could blow any time.
If and when it does, the event will relegate most other imaginable natural disasters into relative insignificance.
At the same time, no one has any idea when Yellowstone will erupt again, and there’s nothing that could be done about it anyway.
So perhaps the best thing to do, if you haven’t already, is to go see Old Faithful and the other remarkable sights and animals of this remarkable place while they’re all still there!
What do you say? Have you been to Yellowstone? What was your experience there? And what do you make of the notion of this huge volcano erupting again? Comment below or on our Facebook page.
What you can do: Nothing that’s going to stop nature taking its course. But there are lots of places to learn more about this remarkable place. There’s more detail about the latest discovery here. And more about the recent rise and fall of the ground here. And there are many sites to learn about Yellowstone, including this one from the National Park Service.