The Yellowstone Caldera

So, in trying to come up with a free-form article, I decided I would talk about something that was inevitable. I’ve checked through the blog, and I’m fairly sure no one else has decided to look into this subject. That surprises me a little bit, but perhaps nobody’s looked into it because it’s too obvious of a topic? (Please correct me if it’s been talked about already. I could have missed it somehow.)

I’m referring to the Yellowstone Caldera, otherwise known as the Yellowstone Supervolcano. Yes, the very geothermic events which bring us the wonders of the nation’s “Wonderland” have a violent history.

Some years ago, I remember hearing about this topic and seeing a lot of it on networks like The Discovery Channel and National Geographic. I decided I would do an overview of what this Supervolcano is to people who aren’t in tune with it.

So what is a supervolcano? In layman’s terms, it’s a pretty dang big and powerful volcano. Specifically,  a supervolcano has had (or will have) a magnitude 8 on the Volcano Explosivity Index (VEI). And what is the Volcano Explosivity Index? This VEI is a general measurement of the power of an eruption. It measures the volume of a volcano’s ejected material, and the height of the explosive column. And these are measured in “magnitudes.” So what is a magnitude 8 eruption? Well, according to the officials, a VEI 8 eruption sends a volume of ejected material greater than 1,000 cubic kilometers (240 cubic miles) from the point of eruption. To put this into perspective, does anyone here remember the famous eruption at Mt. Saint Helens in 1980? The deadliest and most destructive volcanic event in the history of the United States? Its explosion sent debris 1.2 cubic kilometers outward. That’s only a fraction of the power of what a supervolcano can produce.

But wait. Didn’t I just say that there was one of these things in Yellowstone National Park? Yes, I did. Underneath Yellowstone National Park is a type of volcanic formation called a caldera.

A map showing the range of the Yellowstone Caldera; its rim is marked by the red dotted outline.

So what’s a caldera? A caldera is a bowl-like volcanic feature usually formed when land collapses after a volcanic eruption. The collapse is triggered with the emptying of the magma chamber beneath the volcanic edifice above it. The chamber cannot support the weight, and collapses in on itself.

Sometimes, magma can reenter the caldera, and cause it to rise in what’s called a “resurgent dome.” The pressure will eventually cause these to explode again, which could create another caldera. Yellowstone National Park has the features of a resurgent dome, and some geologists predict that Yellowstone could erupt again, with catastrophic effects that could devastate not just the whole country, but drastically affect the world’s climate.

So there you have it. Underneath one of our national treasures. Underneath a landscape that people once thought to be a hallucination. Underneath a landscape revered by artists and explorers. Underneath the “Wonderland” that became not just the United States’, but the world’s first National Park, is a massive, magma-filled bubble that’s seemingly ready to burst. It has been labeled as a supervolcano, and has erupted in the past. And if it erupts, it will most likely live up to this label.

So what can we do to prepare for a catastrophic explosion? Honestly, probably not much. Such an explosion would, one as explained earlier, scatter at least 1000 cubic kilometers of volcanic debris across the region. Areas in the surrounding states of Montana, Idaho, and Wyoming would be immediately affected. Furthermore, there would be a dramatic change in the world’s climate. The eruption would likely cause the creation of another caldera, and the process could likely repeat.

However, I should point out that this no cause for immediate alarm. The USGS asserts that many scientists are not convinced that a catastrophic explosion will not only not happen within the next couple of centuries, but aren’t even convinced that another catastrophic eruption will ever happen in Yellowstone again. The USGS explains that given Yellowstone’s eruption history, the probability of another caldera-forming eruption is extraordinarily low. The probability is low enough to be compared to the probability of a 1 kilometer asteroid hitting the planet. And such events are neither frequent or predictable enough to estimate.

But nevertheless, the study of Yellowstone’s volcanic activity continues. As the research continues, scientists begin to get a better sense of the Yellowstone Supervolcano’s activity and what the future has in store for the nation’s first, set-aside, scenic Wonderland. Perhaps this threat of volcanic danger adds to our contemporary notions of the sublime in nature.

Not many things are more powerful and show nature’s mystery and danger than a volcanic eruption.


Sources and Further Reading:

National Geographic Daily News – Yellowstone Supervolcano Discovery—Where Will It Erupt?

USGS: Volcano Hazards Program – Yellowstone Volcano Observatory

Also check out Wikipedia’s entry on Calderas for more links.


2 thoughts on “The Yellowstone Caldera

  1. I’m surprised no one has written about this topic as well. I myself am very interested in this. To think that there is a semi-dormant super volcano lies beneath a beautiful landscape like Yellowstone.. I want to say that the Discovery Channel did a special a few years ago on the “what if” scenario of Yellowstone erupting. The amount of devastation that would result from one such eruption would be catastrophic to say the least. Here is a link I found on YouTube of the Discovery Channel FYI podcast regarding this topic.

    Thanks for the article Tom.

  2. When I read this part of your blog, “So there you have it. Underneath one of our national treasures. Underneath a landscape that people once thought to be a hallucination. Underneath a landscape revered by artists and explorers. Underneath the “Wonderland” that became not just the United States’, but the world’s first National Park, is a massive, magma-filled bubble that’s seemingly ready to burst,” I laughed out loud. When I camped in Yellowstone I was in an area where you can really get a sense that you are in the caldera — the area, near the Madison River, is relative flat and the mountains rise up around you at almost straight angles. It kind of feels like you are on a table or platform that has dropped. Also, everywhere you go, there is steam or boiling water bubbling out of the ground somewhere near by (always stay on marked trails in this park). It didn’t negatively affect my camping trip there, but I will admit that I thought about it and entertained some “what if” thoughts….

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s