Chapter Content
Okay, so like, you know, I was reading about Yellowstone National Park the other day and it's, like, kinda crazy. So, this geologist, Bob Christiansen, back in the 60s, he was looking at the volcanic history of Yellowstone, and he realized something weird: he couldn't actually find the volcano. I mean, nobody else had really thought about it before, which is kinda surprising, right? Everyone knew Yellowstone was formed by a volcano, hence all the geysers and steam vents, and volcanoes, you know, they're usually, like, pretty obvious. But Christiansen just couldn't find it. Especially this thing called a caldera.
See, when you think of a volcano, you probably think of Mount Fuji or Kilimanjaro, you know, like a cone shape. That's just lava piling up. And those can form pretty fast. Like, this farmer in Mexico, he was totally surprised when smoke started coming out of his field, and like, a week later, bam! He had a 500-foot-high volcano. But there's also these other kinds of volcanoes, the ones that don't make mountains. These are the super powerful ones, right? They basically explode and leave this giant, sunken crater, a caldera, which, apparently, comes from Latin and means "big pot." Yellowstone, apparently, was one of those, but Christiansen just couldn’t see it.
Then, NASA, they were testing out some new cameras and took some pictures of Yellowstone. And, uh, some official, being thoughtful, gave some of the pictures to the park. Christiansen saw them and, boom, realized why he couldn’t find the caldera. The whole park, like, the entire 3,500 square miles, *is* the caldera. It’s, like, this massive crater, almost 40 miles across, too big to see from the ground. Yellowstone basically got blown to smithereens at some point. And the force of it was bigger than anything humans have ever seen.
Turns out, Yellowstone is a freaking supervolcano! It sits on top of this huge hotspot, a reservoir of molten rock. This reservoir goes, like, at least 120 miles deep into the earth, all the way up to just below the surface, creating what they call a superplume. That's where all the heat comes from that powers all those geysers and hot springs, the bubbling mud pots. And underneath all that is a magma chamber, roughly the size of the park itself, about 45 miles wide, and, at its thickest, like, eight miles deep. Imagine a pile of TNT the size of a county, shooting eight miles into the sky! That’s, like, what Yellowstone visitors are walking on. The pressure of all that magma, right, has actually pushed the whole park and the area around it up, like, a half-mile higher than it should be. If that thing blows, well, it's pretty much unimaginable. One expert said, if it goes off, "You couldn't get within 600 miles of it." And it could be even worse than that.
So, the thing about these superplumes, like the one under Yellowstone, is that they're shaped kinda like martini glasses, narrow at the bottom, but then they spread out near the surface, becoming these big bowls of unstable magma. Some of these bowls can be, like, 1200 miles across. Now, the theory is that these superplumes don't always erupt violently. Sometimes they just ooze lava, you know, like what happened in India 65 million years ago with the Deccan Traps. That superplume covered almost 200,000 square miles and the toxic gasses, uh, probably didn't help the dinosaurs out too much, right? Superplumes might also be responsible for the rifts that break continents apart.
These hotspots, they're not that rare. There are, like, 30 active ones on earth right now, and a lot of famous islands are related to them. Iceland, Hawaii, the Azores, the Canary Islands, the Galapagos... you name it. But most of them are in the ocean. Yellowstone, for some reason, ended up on land. The only things we know for sure are that the earth's crust there is thin, and it's really, really hot underneath. And there's a big debate about whether the hotspot made the crust thin, or the thin crust caused the hotspot. The continental crust has a big impact on how these things erupt. Other supervolcanoes tend to be kinda chill, oozing slowly. Yellowstone? It goes boom. It doesn't happen often, but when it does, you want to be far, far away.
The first eruption, that they know of, was like, millions of years ago. And there have been about 100 eruptions since then, but only three recent ones that have been documented. The last one was, like, 1000 times bigger than Mount St. Helens. The one before that was 280 times bigger. And the one before *that* was, like, who-knows-how-many times bigger, at least 2500 times bigger than Mount St. Helens, maybe even a terrifying 8000 times bigger.
We don’t really have anything to compare it to. The biggest one in recent history was Krakatoa in Indonesia. The sound traveled around the world for nine days! And the waves reached all the way to the English Channel. If you compared the material from Krakatoa to a golf ball, then the biggest Yellowstone eruption would be this huge boulder you could hide behind. Mount St. Helens would be like, a small bean.
The ash from a Yellowstone eruption from millions of years ago, that would bury New York State under 65 feet of ash, or California under 20 feet. And that ash is what created these fossil beds that were found way out in Nebraska. The eruption happened in Idaho, but the earth's crust has shifted, so now it’s under Wyoming. The hotspot, it’s still there, like a blowtorch aimed at the sky. And it’s left behind fertile volcanic plains, perfect for growing potatoes. Geologists joke that in another couple million years, Yellowstone will be making French fries for McDonald's, while people in Billings, Montana, dance around the geysers.
The last Yellowstone eruption, it covered almost the entire area west of the Mississippi River in ash. And that area, that’s the breadbasket of America. It produces half the world’s grain. And remember, that ash doesn't melt like snow. You gotta find somewhere to put it. It took thousands of workers months to clear, like, 180,000 tons of debris from the World Trade Center site in New York. Think about how long it would take to clear Kansas.
And we haven't even talked about the effect on the climate. The last supervolcano eruption on earth, that was in Toba, in Sumatra, Indonesia, like, 74,000 years ago. Nobody knows how big it was, but it was massive. Ice cores from Greenland show there were at least six years of "volcanic winter" after the Toba eruption. And who knows how many bad growing seasons after that. It's believed to have almost wiped out humanity. The global population dropped to maybe a few thousand people. Meaning those few thousand are the ancestors of all of us, which explains why we have so little genetic diversity. Anyway, there's evidence that the world’s population didn’t recover for another 20,000 years. It takes a long time to recover from something like that.
Okay, so all that's interesting, right? But it was kind of theoretical. But then, something weird happened. Suddenly it seemed way less theoretical. The water in Yellowstone Lake started spilling over the banks at one end, flooding a meadow. And at the other end, the water was mysteriously disappearing. Geologists went to investigate, and they found that a huge part of the park was bulging upwards. It was like raising one side of a kid’s paddling pool. By the mid-80s, like, this whole area, over 40 square miles, was, like, three feet higher than it was in the last survey. Then it dropped again. And now it seems to be rising again.
Geologists figured there was only one explanation: an active magma chamber. Yellowstone wasn't just some ancient supervolcano. It was still alive! And around that time, they estimated that Yellowstone has a major eruption, on average, every 600,000 years. The last one was 630,000 years ago. So it’s, like, due, right?
A geologist at Yellowstone, Paul Doss, he put it this way: "I don’t think it is, but you’re standing on the world’s largest active volcano." He was this super-friendly guy, not at all what you'd expect. Gray beard, ponytail, sapphire earring. He was actually a blues musician who played glass chimes. But he knew and loved geology. He said Yellowstone was, "The best damn geology in the world." You know? We drove around the park that day, and he showed me all these amazing things, like, the mineral springs, the rocks that are almost three billion years old. It’s all so clear there, and so beautiful. He totally loved it there. He said the winters were cold and the pay wasn’t great, but when the weather was good, it was amazing.
We were talking about what causes Yellowstone to erupt. And he said, “Nobody knows. Volcanoes are weird. We just don't understand them.” He mentioned Mount Vesuvius in Italy, it was active for, like, 300 years, then just stopped. Some volcanologists think it’s building up energy again, which is kinda scary, cause there’s millions of people living around it. But nobody can say for sure.
I asked him how much warning we’d get if Yellowstone was about to blow. He just shrugged, “Nobody was around for the last one, so we don’t know.” It could be earthquakes, the ground swelling, changes in the geysers, but really, who knows?
So, it could just go off without any warning? He nodded. The problem is, almost everything that could be a warning sign already happens in Yellowstone all the time. Earthquakes are usually a sign, but there’s tons of earthquakes there all the time. Changes in the geysers, that could be a sign, but they’re always changing anyway. Old Faithful used to be super regular and shoot up, like, 300 feet. Now it’s different. Steamboat Geyser is the biggest in the world, but it can erupt every four days, or every 50 years! The whole park’s just unpredictable, right? So you can’t really draw any conclusions from anything.
Evacuating Yellowstone wouldn't be easy either. There are, like, millions of visitors there, mostly in the summer. And there aren’t many roads, and they’re deliberately narrow, to slow people down and protect the scenery. But also because of the terrain. In the summer, it can take hours just to get anywhere in the park. And people stop everywhere to look at animals. You’ve got bears, bison, wolves...
Anyway, they formed something called the Yellowstone Volcano Observatory. This was a while ago, right? It's not so much an organization, more of an agreement to coordinate research and analysis of the park’s geology. The first task was to create an "Earthquake and Volcanic Eruption Contingency Plan."
They didn't have one? Nope. Not yet. But they were working on it. Apparently, Christiansen, along with two others, was going to assess the danger and make recommendations to the park superintendent. The superintendent would decide whether to evacuate the park. As for the surrounding areas, well, you're on your own. If Yellowstone really blew, this plan wouldn't solve much.
Of course, maybe it won't happen for thousands of years, or maybe it won’t happen at all. It could be that we’re in a long period of quiet now. The signs suggest that the magma chamber is cooling, becoming crystalline. It’s just letting off steam. You need to hold onto that steam to get a big eruption.
Still, there are other dangers in and around Yellowstone. Like, what happened in the Hebgen Lake area. There was a massive earthquake, and it triggered a huge landslide. Millions of tons of rock came crashing down the mountain, and it wiped out a campground. Dozens of people died. It all happened so fast, right? The people in one tent survived, but their parents in the next tent, they were gone.
“Big earthquakes, I mean *big* earthquakes, they’re gonna happen,” Doss told me. “I guarantee it. This is a big fault zone. We get a lot of earthquakes.”
Despite the earthquake and the other dangers, they didn’t put in permanent seismographs in Yellowstone until the 70s.
If you want to see the power of geology, check out the Teton Mountains. They’re located south of Yellowstone. The Tetons didn't even exist, like, millions of years ago. The land around Jackson Hole was just a high, grassy plain. But then, a fault line appeared in the earth. And, every 900 years or so, the Tetons would have a major earthquake, big enough to lift the mountains a few feet higher. Over millions of years, that’s how they got to be, like, 7000 feet tall.
But, that average of 900 years, that's misleading, right? The last major earthquake in the Tetons was thousands of years ago. So they're probably the most overdue place on earth for an earthquake.
Thermal explosions are also a big danger. They can happen anywhere, anytime, and they’re totally unpredictable. Yellowstone has more geysers and hot springs than anywhere else in the world. And, like, nobody knows when a new vent will appear.
There’s this place called Duck Lake. It looks like a peaceful pond. But there wasn’t a pond there before. There was a huge explosion! Millions of tons of mud and rock and superheated water, it just exploded. You can imagine if that happened under the Old Faithful parking lot, or at a visitor center. He looked grim.
Would there be any warning? Probably not. The last big explosion in the park was in the late 80s, at a place called Porkchop Geyser. It left a, like, 15 foot wide crater. So, not that big, right? But if you’d been standing there, it would have been plenty big. Luckily, nobody was. But it happened without any warning. It's happened before, like, in the past there have been explosions that leave a mile-wide crater. You just have to hope you’re not standing there when it happens.
Rockslides are also a danger. There was a big one in Gardner Canyon. Luckily, nobody got hurt. And at another place, there’s this rock hanging over a road. There are cracks in the rock. Doss said it could fall anytime, like, he wasn’t joking. People drive under that rock every single day, and it’s full of tourists. It might last for decades, he said. You just have to accept the risk when you come to a place like that. That’s just how it is.
Most of the time, nothing happens. The rocks don’t fall, there’s no earthquakes, no new vents. Despite all the instability, things are mostly safe. It's like the earth itself, you know?
Yellowstone is dangerous for the visitors, but it's dangerous for the employees, too. Doss told me this story about three summer employees who went skinny-dipping in a hot spring. It’s illegal to do that, right? And even the water isn’t always boiling. Some of the water you can just hang out in. But what they didn’t know was, there are these thin crusts of earth, and underneath them are, like, scalding vents. They got lost, and they fell into a boiling pool. Nobody made it.
Before I left the park, I went to check out the Emerald Pool. It’s a historic place. A team of biologists scooped up some brown scum and studied it for a lifetime. They found all these living microorganisms. Extreme microorganisms, you know, that can live in water that’s too hot or too acidic, or full of sulfur. The Emerald Pool had all those terrible conditions. And these microorganisms thought it was fine! They called them *Sulfolobus acidocaldarius* and *Thermus aquaticus*. They used to think nothing could survive above a certain temperature. But these things were chilling in water that was way, way hotter.
And one of those new microorganisms, *Thermus aquaticus*, this scientist discovered that the heat-resistant enzymes could be used to perform this chemical magic called the polymerase chain reaction, PCR. Scientists could use tiny amounts of DNA to create huge amounts of DNA. It became the foundation for genetic science. It was used for academic research, police forensics, everything. And this scientist won the Nobel Prize for it.
Scientists have been discovering even more heat-resistant microorganisms. They're called hyperthermophiles, and they need temperatures above 176 degrees Fahrenheit. The most heat-loving microorganism is *Pyrolobus fumarii*, and it lives in the walls of deep-sea vents. That’s, like, 235 degrees Fahrenheit. The upper limit for life is supposed to be around 250 degrees Fahrenheit, but who knows, really.
So the discovery of these microorganisms completely changed the way we think about life, right? Wherever we go on earth, even to the most inhospitable environments, if there’s liquid water and some kind of chemical energy, there’s life.
Turns out, life is a lot smarter than we thought. And more adaptable. Which is a good thing, cause the world doesn’t seem to want us here.