There seems to be some kind of cycle. Ever since it became widely known that Yellowstone was actually a giant big-ass freaking volcano, there’s been this cycle that goes as follows:
1. Minor uplift and or earthquake
2. Someone on the internet notices
3. Hysteria, conspiracy, and ridiculousness
4. Scientists facepalm, rend their hair, wreck their edges, and sob. YES. YOU ARE MAKING THEM CRY, AMERICA.
It seems to run on a yearly cycle. And that cycle is upon us. Sigh.
Last week, on the 30th, there was a minor earthquake. There are minor earthquakes every day, dozens of them, everywhere. This one happened to have the misfortune of nucleating 3.5 miles underneath the surface about 4 miles northwest of the Norris Geyser Basin, in the northwest corner of Wyoming, within the park. It was mostly reverse faulting, with just a bit of strike-slip motion (which, by the way, is not indicative of rising magma about to explode forth and end human civilization). It made another mistake. It nucleated beneath an area of the caldera that is undergoing an active uplift and is very hydrothermally active. Big fucking mistake, earthquake. You’ve made everyone hysterical now. They were getting that way when a seismometer failed earlier this winter, and the ZOMG DOOM brigade thought harmonic tremor had begun under the park (IT DIDN’T. PLEASE SHUT UP, STUPID PEOPLE.)
The earthquake was the “biggest in thirty years” which is actually true. Biggest earthquake Yellowstone’s ever had was an M7.5 in 1959. Perhaps Yellowstone exploded shortly after that and all that exists now exists in someone’s white-light hallucination just before they die of starvation from volcanic winter.
No, that didn’t bloody freaking happen.
The internet is currently on Defcon Hysterica and it’s really kind of sad to see this all the time. Other countries that host gigantic sleeping calderas don’t have these levels of idiotic hysteria. Three MILLION Italians LIVE in a gigantic caldera named Campi Flegrei that is FAR more active than Yellowstone, and volcanologists are actually FREAKING WORRIED about that one given its potential. It has actually erupted WITHIN THE RECENT PAST. Tens of millions of Europeans live within range of the Laacher See, a gigantic caldera in Germany. Ordinary Italians and Germans are not hysterical about their big-ass calderas (although perhaps Italians probably should be and very likely are updating their disaster plans just in case). Why are Americans so gotdamb fucking stupid?
Okay, I’m getting mad, so let’s dial it back.
Let’s talk about Yellowstone.
YES. IT IS A VOLCANO. AND A REALLY BIG ONE. That’s true. How’d a big-ass volcano get into Montana and Wyoming? Well, technically, it didn’t. Wyoming and Montana came to it.
USGS
Yellowstone sits on top of a hotspot. As North America has slowly moved generally westward relative to other tectonic plates, the hotspot has dragged itself under the North American continent. It’s left a clear path too, the Snake River Plain is evidence it was there. This process took millions of years, and as North America continues its trek westward, the hot spot will appear to move generally eastward relative to it. It’s actually not really moving. Hotspots are (relatively) stationary plumes that erupt upward from the mantle. I say relatively because, well, they might also be in motion relative to other hotspots. Geologists discuss these things. They know these things. They don’t get hysterical about these things, although there most certainly are some very strong feelings about mantle plumes!
Hawaii is a hotspot. The aforementioned Laacher See in western Germany is a hotspot. Bermuda may have been a hotspot. Iceland is also a hotspot. The Azores are a hotspot. There’s a hotspot under Cameroon, giving it an active volcanic field where there otherwise should not be one. The Galapagos are a hotspot and Reunion in the Indian Ocean is a hotspot. And so on. Earth has lots of these. It’s not a big deal.
“But Mr. Pinder! Mr. Pinder! Yellowstone erupted 1.4 million years ago and then 600,000 years ago so that means we’re overdue! We’re all gonna die!”
Oh dear, Billy. No, honey. No.
Let’s learn one new thing today. If this is the only thing people learn out of this, I’ll be so very, very happy.
That thing is: there’s no such thing as overdue, not in earth science terms. Nosiree, nope.
Repeat it with me. “There’s no such thing as overdue.”
Now for emphasis: There. Is. No. Such. Thing. As. Over. Due. Well, except for your bills and your library books and apparently Jessica Simpson for those 28 months that she was pregnant a couple years back. And (technically speaking) Malaysian Airlines flight 370 and the SS Cyclops.
I’ll explain, and I promise, I’ll be nice about this, because it’s vitally important we get this down.
We’ll use a volcano whose moods are fairly well known, and then we’ll use various seismic faults to demonstrate the nonsense that is the word “overdue” in this context. It will be fun.
Mont Pelee sits at the north end of Martinique in the Caribbean. It’s a beautiful mountain, with verdant slopes. It acts as a catch for clouds; the north end of the island receives far more rain than the south end.
It’s also a mountain that is moody as all fuck. In 1900 or 1901, it woke up and by the spring of 1902 it was in a really bad mood. In May, on the 8th, just before 8 a.m., it exploded during an eruption that had been going on since the middle of April. The pyroclastic flow from the explosion obliterated the large city that sat at its foot within minutes. Of Saint Pierre’s population of roughly 30,000, there were exactly two survivors although some accounts say three. The eruption killed about 16% of Martinique’s 1902 population in just under five minutes.
Scientists have since learned (Pelee went back to sleep in 1905, and has mostly remained that way since, save an eruption from 1929 to 1932) that Pelee has erupted some fifty four times since about the year 8400 BCE, twenty of them being in the last 5,000 years. It’s been just over a century since the last one, and research indicates there’s perhaps about a century between eruptions, so is Pelee about to explode and obliterate the now much diminished Saint Pierre again?
Probably not!
See, volcanoes aren’t regular and they even have eruptive types that vary. Pelee has four. It spits up pumice and gas. It has moderate eruptions with a bit of ash flow. It has eruptions that grow “lava domes” within the crater (the 1929 eruption was of this type), and it has eruptions that send superheated death clouds of superheated ash and gas down upon nearby cities. The three known historic (meaning, they were observed by Europeans who wrote about them) eruptions prior to 1902 were small. The one that happened around 1340 was probably as monstrous as the one that cooked some 30,000 people alive in 1902. Today, thankfully, Pelee is well monitored and the complex social conditions that existed in 1902 don’t exist now. We know a great deal more about volcanic eruptions now than we did in 1902, thanks in part to Pelee’s obliteration of much of the north end of Martinique in its 1902-1905 eruption.
What does this have to do with Yellowstone? Quite a bit actually. Yellowstone’s last known magmatic eruption wasn’t 600,000 years ago. It was 70,000 years ago. And like Pelee, Yellowstone has patterns that vary, which we can recognize. Its cycles are pretty simple and from them we can infer that if Yellowstone were to engage in a period of eruptions within the near geologic future, they’ll very likely be small. They might only be hydrothermal explosions—there have been numerous during the Holocene (or, within the last 12,000 years.)
But even using the three known gigantic eruptions that painted almost all of North America with ash, you still don’t get to use the words “Yellowstone is overdue” in a sentence. Let’s do the math, for those who insist.
There was an eruption 2.1 million years ago. There was an eruption 1.3 million years ago. There was one 640,000 years ago. What do those three values average out to? 730,000 years, suggesting, for those who insist the earth runs on a regular clock, we’re 90,000 years away from the next gigantic, civilization ending Yellowstone eruption. Or, what these people say. They’re paid to know these things.
I can’t let this discussion end just yet, because there seems to be some rising hysteria from other quarters about the word overdue. Let’s nip that in the bud right quick too.
Earthquakes, too, do not run on a schedule. Like volcanoes (and hurricanes and floods, and tornados, but we’ll talk about those some other time) there’s no such thing as overdue for earthquakes either.
We unfortunately can’t predict earthquakes. Unlike volcanoes, big earthquakes don’t generally let us know that they’re coming. I have little hope that we’ll ever be able to do so.We know that earthquakes occur on faults. We also know that their aftershocks occur in a fairly predictable pattern. Earthquakes, over all, have no real pattern other than what is expressible as an average.
We can, however, look at past behavior, and from that past behavior, we can infer probability. We tried to predict the future with Parkfield (which was a segment of the San Andreas thought to be as regular as a cuckoo clock), and the Earth decided it had other plans.
For example, we can look at the past behavior of the southern segment of the San Andreas Fault. Of the fault’s three main segments, it is the one that has not had a rupture within the historical period. Nevertheless, evidence of its past behavior abounds. On average, it pops off a large quake of perhaps M7.5 every 150 years. Its last was around 1680. Uh oh.
But wait!
That’s an average. There may have been clusters only a few years apart, and then hundreds, or thousands of years separated those clusters. Adding up the time between them averages out to around 150 years. The time between may not be significant. Statistically, though, I like the following a lot, found here:
The question focus on statistical independence. Each roll of a die is independent, so 20 rolls without a six doesn’t mean a six is due. The odds haven’t changed. As one deals through a deck of cards, the odds change. If you deal 20 cards without a six, the odds of a six occurring increase. I think we can consider an earthquake more like the cards than the dice. Plate tectonics are creating tensions. As these tensions build, it is more likely that there will be some sort of release. By the time you reach the 49th card in a deck without a six, the next card must be a six. If tensions below the surface reach a critical point, there will be a quake. So even if we aren’t ‘overdue’, the possibility for a quake is slowly increasing.
Also, all we have to work with is the historical record, and this is true all over the world. Some examples:
The Hayward Fault under Oakland and Berkeley’s average is about 140 years too. Its last large quake was in 1868. Is it overdue? No! The time-space between earthquakes on the Hayward’s system of faults varies by quite a bit. The AVERAGE is 140 years.
In southwest Oklahoma, on the Meers Fault the last large earthquake was about 800 years ago, and prior to that about 1400 years ago. Two data points suggest 600 years between large earthquakes, but more evidence suggests a very long period between large quakes, perhaps on the order of tens to hundreds of thousands of years.
Elsewhere in the Midwest we all know about the 1811-1812 sequence, and there’s evidence of others going back thousands of years, averaging out to about 350 years or so. But the full story tells us something much different—the seismic zone may in fact be shutting down (this is an area of considerable ongoing controversy within the geologic community).
Evidence tells us Cascadia pops off on average every 300 years but further research tells us this is much more complicated. There’s been perhaps 41 large earthquakes in the last 10,000 years, but the time between them varies, and they’re not all M9s.
In Japan, seismologists and hazard planners there used their long written historical record to calculate an average for the Nankai Trough. While the planning was useful in densely populated Tokyo, which sits at the northeast end of the Nankai, it was eventually to their peril. A different megathrust bought Japan its recent Big One, one they had not considered. This is less a problem with the science and more a problem with how human beings evaluate risk, however.
And so on.
I’m certainly not writing this to say “Don’t worry Los Angeles, you’re not about to get wrecked.” It certainly is of considerable interest that after a fairly quiet interval, faults around the basin have decided to let y’all know that they exist. But they may not be significant, much like the various swarms and uplifts within Yellowstone aren’t, overall, significant. The recent LA earthquakes should be a warning to you to keep your supplies and your disaster plans fresh, not flee from the freaking West Coast in terror. Listent to Dr. Lucy Jones. She knows these things, and is an excellent explainer of all things Southern California earthquakes.
And with Yellowstone, if you insist on being stupid, please shop at Costco. My Roth IRA will thank you. Seriously.
In short, the following:
1. No, the animals are not fleeing the park (and youtube as a source? Are you kidding me? No.)
2. The uplift in the Norris Basin is probably not significant.
3. If you’re going to insist on using overdue, Yellowstone is not, using your stupid “here’s the interval based on three data points” math.
4. Seismographs fail. Please bloody grow up.
5. The USGS is not covering anything up and in fact would warn the public—they did in California when Long Valley decided it wanted to inhale, exhale, and fart in the early 80s (it’s still farting too.)
6. Believe the volcanologists because they know what the entire fuck they’re talking about, that’s a degree that takes ten bloody years to get.
7. There’s no such thing as overdue in this context.
8. If you people insist on freaking out, buy your doom supplies at Costco. If you shop at Costco, they make money. When they make money, their stock goes up. When their stock goes up, my IRA has a tantric orgasm. My statements arrive wet and musky from that afterglow.
9. LISTEN TO THE VOLCANOLOGISTS I MEAN DAMN.
And that’s it. Quit being stupid, internet.