When I moved to Jackson Wyoming, back in 1981, I had never heard of the Yellowstone “caldera.” In fact, I didn’t become familiar with the word “caldera” until a few years later, when the enormous submerged volcanic boil that covers so much of Yellowstone began to be publicly identified. At first, on the Yellowstone maps handed out to tourists, by a tiny vaguely circular line, only visible if you really looked for it. Then, several years later, new maps showed it with a slightly larger, more visible line. At some point in those years, my late husband Jeff Joel, who was also fascinated with the Yellowstone caldera, was one of the co-founders of a short-lived local magazine called, of course! — “Caldera.”
I left “the Hole” in 2002, when Jeff wanted to go to law school, and chose Indiana University in Bloomington. He died of a heart attack after the first semester.
Meanwhile, that storied place remains in my memory and imagination. Current fear porn re: the possible near-term eruption of the Yellowstone caldera, given my herstory with the place during the period when the public was being gradually and subtly informed, through changing maps, of its existence, doesn’t usually magnetize me; but this article, written for Planet Jackson Hole, a great little local paper that started soon after I left town, did.
February 11, 2014
JACKSON, WYO – Yellowstone Supervolcano eruption will be cataclysmic, if not imminent
As learned as Wally Ulrich is about the unfathomable secrets of the terra firma deep, there are times when he just has to speculate, or extrapolate from what data can be farmed from instruments that are forever listening to the subterranean belches of a planet wrapped around a core of molten lava as hot as the sun. To be fair, all scientists like Ulrich can do is guess. It’s hardly a reassuring notion for a general public living atop the world’s largest hotspot: the gurgling, bubbling caldron called Yellowstone.
Ulrich packs plenty of cred. The Wyoming native is founder of Geologists of Jackson Hole, a former state geologist and chair of the state’s Geological Survey Board, and a trustee of the American Geologic Institute Foundation. As many questions as the decorated geoscientist can answer about Wyoming’s unique geology including the fascinating Yellowstone area, it’s the ones he can’t that gnaw at him.
“Kids get just panic-stricken and they don’t know how to deal with it. They’re just terrorized by it,” Ulrich shared after a recent talk he gave to young students about the supervolcano that lurks quite alive and active at the heart of Yellowstone National Park. “The most heart-wrenching questions I’ve ever had to answer came from these kids. ‘If I have to leave my dog will he be here when I get back?’ or ‘Will I be vaporized?’ It just breaks your heart.”
Recent hysteria over off-the-chart readings gleaned from a faulty sensor in Yellowstone set neighbors of the nation’s first national park on edge. In addition, a new study from the University of Utah claims the magma chamber located just three to nine miles below the Earth’s surface is far larger than previously thought: a pocket of hot lava measuring some 55 miles long by 18 miles wide. Frequent earthquake swarms in the Yellowstone region have also alarmed the neighbors. The question on everyone’s lips is the same: Is Yellowstone getting ready to blow?
Doomsday scenario: What if it happened?
Experts say it’s not only residents in the Rocky Mountain region that need to worry about the slumbering supervolcano; when Yellowstone blows it will alter life on Planet Earth as we know it.
Comparisons to the 1980 eruption of Mount St. Helens are often made to help paint a picture of what a major volcanic event in Yellowstone might look like. It’s hardly a fair comparison, and no more accurate than contrasting a firecracker and a hydrogen bomb.
The closest experts can get to what a major eruption in Yellowstone might look like is by studying the Krakatoa blast of 1883. On August 27 of that year the island volcano blew its top, launching debris 15 miles into the atmosphere. Using Krakatoa for comparison, a major eruption of Yellowstone’s supervolcano will be easily heard above the din of New York City traffic. Every seismometer in the world will record the initial shockwave.
Krakatoa rates a 6 on a scale known as Volcanic Explosion Index. By comparison, Mount St. Helen’s had a VEI of 5. The largest ever volcanic eruption recorded in modern times is Mount Tambora, which burst on April 10, 1815. It rated a VEI of 7 and the resulting ash thrown into the sky blotted out the sun for nearly a year. Global temps dropped an average of five degrees causing worldwide crop failures and earning 1816 the dubious title of “The year without a summer.”
How would a Yellowstone eruption compare? Scientists are aware of three major full-scale outbursts in Yellowstone’s history. The latest is an eruption that caused the formation of the Yellowstone caldera. It occurred approximately 640,000 years ago. Before that, major eruptions took place 1.3 and 2.1 million years ago. Each blast was slightly smaller than the preceding one – an indication, according to some scientists, that Yellowstone is cooling off. The latest smaller-scale eruption took place some 70,000 years ago, forming the West Thumb of Yellowstone Lake.
Experts say a supervolcanic event in Yellowstone would be at least 50 times as powerful as the Krakatoa blast and 2,000 times the size of the 1980 Mount St. Helen’s eruption. In short, surrounding communities like West Yellowstone, Moran, and Cody would be Pompeii – buried in more than 240 cubic miles of pumice and ash. They would be the lucky ones.
The eruption would last for about a week. The resulting debris thrown into the atmosphere would obliterate the sun for weeks after, probably months. Worldwide famine would take hold, threatening every species on Earth.
“I would think it would be quite severe,” said Dr. Michael Rampino. Rampino is a professor at NYU in the departments of biology and environmental studies. “First, it would be a problem to get through the eruption. Areas adjacent to Yellowstone would be destroyed by basaltic lava flows.
Volcanic ash would cover the western United States. In the years to come, average global temperatures would plummet. The cooling would be pretty dramatic: 5 to 10 degrees. And that’s Celsius. We’re probably talking 10 to 20 degrees Fahrenheit lower temps around the world.”
Crop failures would result in worldwide famine, Rampino speculated. And there would be nowhere to run. Even tropical regions near the equator would experience frost. Loss of vegetation would result in the extinction of numerous species, especially those already threatened.
“The tropics might be the worst place to be if we get the effects we think we will get from a mega-eruption,” Rampino said. “There is the threat of drought in those regions and populations there are short on food now. Any species not particularly cold-hardy would be in serious trouble.”
Don’t believe the hype
Hysteria over the 1,530-square-mile caldera in Yellowstone has peaked in recent years, owed in part to better and more extensive surveillance of the park’s subterranean nether regions.
Yellowstone has never been more seismically observed than it is now.
Jamie Farrell is a geophysicist at the University of Utah and the lead author of the study that concluded the magma chamber underneath Yellowstone is two-and-a-half times larger than previously estimated. That calculation came as a result of better instrumentation purchased with economic stimulus money in 2010.
Up to 35 seismic stations monitor ground shaking activity in real-time telemetry, reporting the data back to the Geologic Hazards Science Center in Golden, Colorado, and to the University of Utah. Lately, some of the data has been made public on the Internet. Readings at one particular site caused a national stir when the Turner Radio Network reported instrumentation malfunction as an impending sign Yellowstone was about to erupt.
“What happened was someone was seeing this data on the public side and that someone started panicking,” Ulrich explained. “That person paid no attention to the other data and talked to nobody about it. Look, a computer at Golden monitors everything and even before any human sees any data, alerts are posted to some 70 scientists throughout the world.”
One of the first scientists to see seismic readings from some 300 channels coming out of Yellowstone is the USGS scientist-in-charge at the Yellowstone Volcanic Observatory, Jacob Lowenstern. When Yellowstone burps, it’s in Lowenstern’s ear.
“Anytime you have data available to the public they are going to interpret it as they want. That’s why we have people trained to disseminate this information,” Lowenstern said, adding that the x-directional, or the channel measuring up-and-down p-waves at Borehole B944, was malfunctioning.
“What happened was there was just noise on one of the channels. It was not a real signal.”
Channels broadcasting s-waves, or the side-to-side motions of the ground which are not publically available, were reading normal, according to Lowenstern.
“If they want to say they think Yellowstone is getting ready to erupt they can say what they want but there is no logic to it. They are simply not using other tools to be self-skeptical. Just looking at nearby seismometers should tell you that there is nothing going on in that in area.
There can be cultural noise or weather-related noise. In this case, I don’t think we know what the noise was. That particular channel is not working properly and we don’t have the money to go in there, especially during the winter, and get to it.”
Lowenstern added, “For one thing, true geological signals don’t look like that. They start with a peak when the rock breaks and then wax and wane. It’s a rich signal. This [faulty reading] is just constant noise and is the kind of thing you see when there are electronic problems. And you can find this kind of aberrant noise signal every day somewhere on any one of the monitors out there.
If you want to find one of them you can find them. Wind can get people excited. A car going by can get people excited. This person was clearly not trying to understand anything about Yellowstone but was just trying to get people scared.”
New and better science
The ability to measure secondary waves, commonly referred to as s-waves, is relatively new to Yellowstone geoscientists. For one, it has allowed Farrell and his team to more accurately map the magma chamber below Yellowstone. The findings, which were presented to the American Geophysical Union late last year, confirmed what some scientists feared: the amount of hot molten rock that is in some type of liquid state is enormous.
“We can’t use ground-penetrating radar. The only way to measure the magma reservoir beneath Yellowstone National Park is through seismic waves. S-waves do not travel through fluid,” Farrell said.
Lowenstern said the news that Yellowstone was sitting atop a larger pool of lava than previously thought did not surprise him. “I think people expected it before because of the size of the caldera and the heat coming off of it,” he said. “Remember, the magma doesn’t have to be all melt.
Not all of the material is highly molten or eruptible. It’s like a sponge down there in a lot of places.”
Ulrich said these estimations are just that. More accurate technology is either too expensive or banned within a national park.
“No one has been allowed to map it like we do with oil and gas. Mobil and Exxon would use explosives,” Ulrich said. “You can’t do any of this without putting equipment on the ground. We just have to deduce from the number of data we have.”
Ulrich did point out the work of a colleague, Adam Schultz, whose limited research using souped-up, old school geophysical imaging methods like magnetotellurics shows a differing opinion of what may be occurring as deep as 25 miles below the earth’s surface.
Earthquake swarms: Yellowstone breathing
Alarmists often point to the numerous earthquake clusters that occur within the park. Is seismic activity a sign of a supervolcano coming to life or is it a naturally occurring phenomenon of hotspots found also in Iceland and Hawaii?
“Swarms are very common in volcanic settings,” Farrell said. “In Yellowstone, about half of the total number of earthquakes occur as swarm seismicity; most are very small and last one or two days.”
Two such swarms in particular worried some recently. In January 2010, seismic monitors in the Madison Plateau were jumping. Small- to medium-sized earthquakes came faster than could be counted. In all, some 2,500 earthquakes were reported during a swarm that lasted a month. Two years earlier, a 10-day cluster of earthquakes rocked the Yellowstone Lake bed. Nearly 900 earthquakes were recorded in that episode.
Still, they weren’t the biggest. In 1985, more than 3,000 earthquakes jolted the region, centered east of West Yellowstone. The swarm lasted more than 70 days.
“What all of this tells you is that Yellowstone is very much an active volcanic system, and that pressurized areas underneath are nature’s release valve,” Lowenstern said. “People feel them and nobody likes feeling earthquakes, even if they are small. We watch them carefully and we don’t think they indicate anything larger coming. It’s all a balance that keeps the system from erupting. At least for now.”
Farrell agrees. Much of what happens in Yellowstone – from geysers to mudpots to earthquake swarms – is simply evidence of a supervolcano “breathing.”
“These releases are just the way a volcano works,” Farrell said. “When we’ve have had some of these larger swarms, we see they tend to occur right when the caldera is going from inflation to deflation. What we think is that these swarms are evidence that fluids or gasses are coming off the magma reservoir and that allows the caldera to go into a deflation episode.”
Big bang theory: What would a supervolcano look like?
The good news is Yellowstone will not go off overnight. We’ll have warning. Weeks, maybe even months. The bad news is there will be nowhere to go to escape the impending effects, including everything from drastic climate change to economic collapse. In the days leading up to a catastrophic event in Yellowstone, scientists will be looking for a few things.
“We’re not exactly sure how it [will go down]. No one’s ever seen one,” Farrell admitted. “But it will likely start with a series of smaller events, ramping up slowly to a major eruption. It may take weeks, months; we aren’t exactly sure. We expect lots of swarms and a huge change in hydrothermal system with major ground deformation.”
Swarms in the three range on the Richter scale would give way to legitimate tremblors in the five or six range, according to Lowenstern. It would be a clear indication the crust protecting us from the molten lava that causes Yellowstone to steam away all winter was starting to crack open.
“There would be a lot of big earthquakes and people would feel them,” Lowenstern said, describing the end times. “Magma is not going to come out of the ground without earth breaking. We would be looking for ground deformation on the scale of feet. Hot stuff would start intersecting with the park’s hydrothermal system and that would cause explosions. Prior to the last eruption there were lots of lava flows that came out of the ground. So we could possibly see many small ones before a big one.”