Yellowstone Volcanos

Man on a Yellowstone boardwalk in front of a hot springs

Did you know that Yellowstone National Park is actually an active supervolcano? As you walk around the park you may think: “I don’t see any volcanos?!” That’s because much of the entire park is a volcano – and the bubbling geysers and hot springs are an indication of the churning activity below the surface.

Yellowstone Supervolcano

The term “supervolcano” implies an eruption of magnitude 8 on the Volcano Explosivity Index, indicating an eruption of more than 1,000 cubic kilometers (250 cubic miles) of magma. Yellowstone has had at least three such eruptions: The three eruptions, 2.1 million years ago, 1.2 million years ago and 640,000 years ago, were about 6,000, 700 and 2,500 times larger than the May 18, 1980 eruption of Mt. St. Helens in Washington State.

Yellowstone Caldera

Map of Yellowstone Calderas

Map of the Yellowstone Caldera (purple border) with older calderas (green border)

The last time the Yellowstone supervolcano erupted was 640,000+ years ago. The Yellowstone eruption area collapsed upon itself, creating a sunken giant crater or caldera 1,500 square miles in area. The magmatic heat powering that eruption (and two others, dating back 2.1 million years) still powers the park’s famous geysers, hot springs, fumaroles, and mud pots.

Firehole River with Riverside Geyser. Photo by Jeff Vanuga

Did You Know Yellowstone Has 3 Enormous Calderas?

At least 1,299 episodes of unrest have occurred at 138 calderas greater than 5 km in diameter during historical time. Read More...


Docudrama Movie ‘Supervolcano’ by BBC and Discovery Channel

BBC Science and Discovery Channel produced the docudrama called “Super-Volcano,” followed by the documentary, “Supervolcano: The Truth About Yellowstone.” Read More...

Yellowstone's Castle Geyser

History of Yellowstone’s Supervolcano

The Yellowstone area has seen tremendous volcanic activity in its past. 3 giant eruptions have occurred between 2.1 million and 640,000 years ago. Read More...


How Much Notice Before Yellowstone’s Supervolcano Erupts?

How imminent is an eruption of the Yellowstone volcano? And other questions frequently asked about the supervolcano that covers the park. Read More...

Magma plume

How the Yellowstone Caldera Formed

The Yellowstone caldera was formed after an explosion of magma nearly 600,000 years ago. Read More...

Fake Explosion

Is Yellowstone Going to Blow? Exaggerated Reports of Volatility

As long as there’s been a National Park seated on a super volcano, there’s been erroneous reports of impending doom. Read More...

Crust waves of a geyser at Mammoth Hot Springs in Yellowstone National Park

Scientists Find 4X Magma Under Yellowstone’s Supervolcano

Yellowstone’s plumbing system is no larger – nor closer to erupting – than before but now we have advanced techniques to map the system. See animation of magma chamber. Read More...

Geothermic Hotspots In (Yellow) and Near Yellowstone

Scientists study Yellowstone geothermic hotspot

Using thermal satellite images, scientists take the earth’s temperature hundreds of miles away from a destination to hopefully predict volcano eruptions. Read More...


Supervolcano Eruptions

The odds that the Yellowstone supervolcano will erupt are roughly the same as the chances you’ll be struck by lightning: 1 in 10,000 Read More...

Yellowstone Clypsydra Geyser in the Lower Geyser Basin

Supervolcano Under Yellowstone is Twice as Large as Previously Thought

Scientists have discovered that the Yellowstone magma pocket is close to the size when the supervolcano last erupted, 640,000 years ago. Read More...


Testing the Volcano Mantle Plume Theory with Corn Syrup

One scientist tests the theory of mantle plumes by using 200 gallons of corn syrup to represent the Earth’s mantle. Read More...

Yellowstone at the Movies

This is Yellowstone: Movies Featuring Yellowstone

Documentaries aside, movies about Yellowstone National Park tend to focus on fiery natural disasters. Read More...

Geyser in Yellowstone’s Upper Geyser Basin

Yellowstone is Leaking Helium

Yellowstone is releasing a about 60 tons of helium from underground stores each year, an amount hundreds, possibly thousands, of times more than expected. Read More...


Yellowstone Volcano Caldera Rises, Falls and Rises Again

Deep beneath Yellowstone, forces of heat and pressure cause the surface to rise and fall much like the breathing of a gigantic, slumbering beast. Read More...


Yellowstone’s Magma Reservoir Much Larger than Previously Thought

The study reports that the magma reservoir beneath Yellowstone measures 37 miles long, 18 miles wide, and 3 to 7 miles deep. Read More...