When Hephaestus finally gets tired of Zeus hogging all the lethality credit and blows this puppy up- so, assuming a continent-devastating eruption- how much warning are we likely to have? I know we don’t have a lot of observed scientific data on “things that can/will destroy civilization”, but surely seismography has advanced some since 70,000 BC. Are we looking at weeks of heavy rumbles, or will this be a more subtle thing, with tremors that could be dismissed as “normal”?
I have no idea. I do know they had plenty of warning when Mt St. Helens errupted.
I was only 10yo when it happened, but IIRC, they knew weeks ahead of time.
I read once that (no cite at the moment) that it would be a decade(-/+) of increasing activity.
The general rule is, the smaller the eruption, measured by the amount of magma coming out, the shorter the lead time for estimating the eruption. Mt. St. Helens and Pinatubo were large eruptions (vei 2-3) and the magma mobilization were tracked with enough accuracy to predict the blow out within days or months. For a really big eruption that dwarfs these two (yellowstone, lake toba, and la garitta - vei 8-9) the warning signs could come decades ahead.
Katmai, krakatoa, and santorini were bigger than pinatubo or st. Helens and may (my guess) have been predicted with modern methods.
The problem (as I’ve gleaned from Bill Bryson’s book “A Short History of Nearly Everything,” which is awesome but should NOT be treated as a definitive text on seismology) is that Yellowstone is so geologically active anyway that it would be very hard to distinguish the signal from the noise. There are many, many small quakes occurring there, and their strength and frequency change often, so it’s very difficult to establish a pattern even if the ground did give us warning.
Then the challenge will be the fuzz of the timing versus human reaction.
i.e. …
Let’s assume it gets significantly more active than now. Like 10x big quakes. And it stays that way for a year or more. The experts conclude Something is Definitely Up.
So now the experts announce that sometime between 10, 50,and 100 years this thing will blow. And the expected severity is somewhere between wreck a couple US states, wreck the entire US, and wreck the planet.
Ok folks, what now?
We know how to mobilize for a few days or weeks to work a small area about to have, or having just had, a disaster. Think incoming hurricane or the immediate aftermath. Or the follow-on response after an earthquake or tsunami. We know what to do and when to do it.
But what do we do with warnings that something will happen in 10+ years? Folks start migrating out of the Midwest? Sorta like the Dust Bowl migration, but with zero cause to leave on this particular fine Spring day, other than a warning about something huge & presently invisible that might happen after your kids are elderly?
My bottom line is society & human nature are not well-suited to reacting to any threat, large or small, whose arrival is more than a few months in the future or whose uncertainty is more than (WAG) 50% percent in time or in severity.
We will almost certainly get plenty of warning, but the big question is, will we recognize it? We’ve never seen a volcano that big blow up before, and it’s always coming up with new and interesting things to do that we haven’t already seen. Maybe one of those new things is the warning, and we’ve already gotten it.
First, your insurance rates will go up.
So what could we do to prevent it being world-destroying? If we a big enough reservoir over top of it, would that blunt the force and catch the ash and dust? Or would the water cool down the surface of the earth there too much, making the top layer of earth too cold/rigid, thereby making the inevitable eruption even more extreme?
You make this HUGE cork…
It wouldn’t be world-destroying, based on the three known eruptions in the past. The western half of the United States would be in bad shape, and maybe there would be a few years of global cooling that played havoc with world agriculture. The biggest unknown would be whether increased seismic activity signaled an impending supereruption, or “merely” a basaltic lava flow, which have taken place more frequently. Smaller hydrothermal eruptions have taken place also, which while locally significant did not impact distant areas.
Eventually evacuation plans would have to be put into place via FEMA or the equivalent. My guess is that businesses would start to be less interested in investing in the west, would start considering basing their assets elsewhere, and fewer people would migrate there. Real estate prices would take a hit. Once you were down to the last few months/ year, when smoke and ash were spewing into the air, people would start migrating out of the area. Maybe there would first be a federally ordered evacuation of the immediate surrounding area, with the evacuation zone expanding as the estimates became sooner and/or worse.
The biggest immediate problem would be ashfall. It’s thought that previous eruptions caused massive wildlife death due to the effects of breathing ash. Filtering masks and systems might make it feasible to shelter in place in the lesser affected regions. Long term, it becomes a political and economic question of the US dealing with a cataclysmic blow that sharply reduces its economic output.
Surely ashfall will be a very short-term thing, ending with the first rain? In the longer term, it should be a huge boon to the US as volcanic soil is super-fertile.
I know you say that as a joke, but perhaps it might actually be better to initiate the eruption early, before the pressure builds too high?
Katmai erupted in June and dumped three feet of ash on Kodiak Island and as far away as Washington, about 2400 miles. It’s estimated that atmospheric ash didn’t disappear until October.
An epic last entry to the pimple/boil thread.
Wouldn’t want to be on those drill rigs. 
From what I see, middle US could be covered in 6" or so of ash. Say goodbye to transportation and food production. Because of prevailing winds, California should be OK, but without the ability to transport the food or oil or any thing else, well…
Did you mean six feet of ash? Because there are rock formations out west that are solidified beds of ash from previous eruptions. And judging from the Vesuvius/ Herculanum example, the first rain would turn the ash into cement.
A proposal to this effect has already been promulgated!
A Russian ‘Doctor of Military Sciences’ says Moscow should just nuke Yellowstone if tensions boil over, Amanda Macias, Business Insider, April 1, 2015.
(Note the publication date. That might be relevant to take into consideration. OTOH, a Google search finds many sites carrying the story or similar.)
I will not worry until I start hearing politicians start saying “I am not vulcanologist…”.
Sort of like a preemptive nuclear strike?
Small comfort to a Kansas farmer whose home, barn and crops are under 3 feet of gritty ashfall cement.