How Bad Would A Yellowstone Eruption Be?

image source: National Geographic

Mount St. Helens was tiny compared to the most dangerous category of volcano – the super volcano. The Yellowstone super volcano is located in the Yellowstone National Park of Wyoming. Try to imagine a volcanic eruption 10,000 times stronger than Mount St. Helens – an eruption that would threaten our very survival.

The image above illustrates the size of the Yellowstone super volcano magma chamber superimposed in 3D beneath the state outlines of Wyoming and Idaho. Notice the relative size compared with the green outline of Yellowstone National Park and the red outline of the caldera itself. It’s huge.


Possible Super Volcano Effects

Magma-Ash-Ejecta-Debris would be hurled 30 miles up into the atmosphere

Near devastation of an area the size of North America or Europe

Devastation resulting in economic collapse

Volcanic ash would cover the devastated area to depths ranging from hundreds of feet within proximity, to as much as six inches – thousands of miles away

Anything within 500 miles of the eruption would be completely destroyed

Ash would circle the globe on upper-level winds blotting sunlight for months, followed by a dim and cold volcanic winter lasting for several years

Global temperature would drop, perhaps as much as 20 degrees F

Mini Ice Age

75% of all plant species would die off

World agriculture would be devastated

Mass starvation

Human survival and civilization as we know it would be threatened


Super Volcano locations include…

  • Yellowstone in Wyoming (USA)
  • Long Valley in California (USA)
  • Valley Grande in New Mexico (USA)
  • Lake Taupo (New Zealand)
  • Aira (Japan)
  • Lake Toba (Sumatra)
  • Siberian Traps (Russia)

super volcano locations

A somewhat alarming statistic regarding Yellowstone is that it’s eruption cycle is a short as the 600,000+ year range and as long as 800,000 years. The last eruption was 640,000 years ago, and we are now within the time frame of possibility. Having said that, it is possible that we will not witness this eruption in our lifetime.

When considering the effects that such an event would have upon the world, it is nearly incomprehensible to create a survival plan.

When considering Yellowstone for example, those who live anywhere near it or downwind from it will have a terrible if not impossible chance of survival. Much of the United States will be covered with ash. Depths would range from 100 or more feet deep near Yellowstone, to 10’s of feet deep further out and even a minimum depth of 5 inches at the extremities of its reach across much of the country.

To put the amount of ash into perspective, the amount of ash and ejecta from Yellowstone could be as much as 11,000,000,000,000 cubic meters (11 trillion), or 2,600 cubic miles.

Preparedness for a super volcano eruption involves location location location. Far away from the immediate ash-fall effects and away from population density where troubles will surely arise in a collapsed aftermath. Several years of stored food. The ability to grow your own food – which may itself be difficult due to the sun being blotted and dim – especially the first year.

Fortunately, the probabilities of are statistically low.
However we just don’t know when…


  1. have you seen the postings/video of the buffalo supposedly leaving Yellowstone (in anticipation of some “event”)?

    watched it, the buffalo are running down a road, but , hard to know…

      1. ok, thnks.

        so, what do you (all) think.

        is it a stampede out of Yellowstone,
        are they being herded off to new pasture/grazing grounds?

        if first, does seem concerning….as I recall, after the big tsunamis, it was noted that very very few animals died (unlike people), the animals somehow knew ahead of time and head for safer/higher ground.

        1. this is just routine migration of the buffalo. not that the caldera isn’t a risk, just that we might not have much warning at all when it does blow. could happen today, could happen 100’000 years from now.

        2. Always look and see what animals do. They have a built in knowledge that we are not aware of. During some Tsunamis some people were saved cause they saw animals heading to higher ground. Wild animals are the best indicators BUT pets have been known to give/show warnings prior to natural disasters

    1. im not concerned half as much with buffalo, as i will be when birds and most other animals run away. it wont just be a short video of 40 to 60 buffalo running along a road. if they were running away from something, im pretty sure they wouldnt all be traveling in almost single file at different paces. there would be a mass migration, with birds leading the way, followed by numerous other herbivores and carnivores. it wouldnt be basically life as usual for them. yellowstone has not caused any trouble yet, so it might be awhile before she’s ready to blow. the most scientists are telling people is that you need to be prepared IN CASE yellowstone decides its ready.

      1. It would mean predators and prey running alongside each other, unconcerned about proximity, just needing to get away. When you see THAT, you know there’s a serious problem.

    2. If you have seen the film The Road. Then all of the USA would be finished in such a volcanic eruption happened at Yellowstone park no food and starvation on a par with a nuclear war

  2. so, for the uninformed amongst us, what do you suppose the circumference of a major Yellowstone Eruption would be?

    How far would the effects reach into Canada?
    Would it effect Alaska? Mexico?

    1. I think that alaska will turn into a tropical paradise for a fews years or maybe even forever. I think it would be like living on the equator. And canada will be covered in ash. There might be animal and human life loss.

    2. depends on wind. the immediate blast won’t affect more than a few states, but in terms of ash dispersal it’s all about weather.

      1. Only a few states….. oh that doesn’t concern you because you must not live in those “couple of states” WOW that pretty cold if you ask me. I live in Idaho, i have two small children.

    3. We need to pray and ask God for mercy for this not to happen. He created the earth and he answer prayers this my encouragement.

  3. the listed effects are false.. It would not hurtle the world into an ice age. The Devastation would range from 100miles of complete destruction to 500miles of Devastation. Only thing to worry about would be mass causalities on the west coast + leaving the country Seriously Vulnerable to possible attack.

    1. A super volcano triggering an ice age is debateable and there are lots of opinions. Google it and you will find varied reports and studies. Some support the theory and others are on the fence. Personally I think it could happen, a mini ice age.

      There is no disupting that global temperatures will drop. By how much? Hard to say. Will it cause mass crop failures? Definetely yes.

      A super volcano eruption in the United States in my opinion will trigger an economic collapse. Our society cannot survive a major economic collapse.

      Those who survive the ash-fall will be left in chaos. Distriubtuion will be down. Planes and Vehicles will fail from the ash intake to their engines. The result will be mass casualty.

  4. One also needs to prepare for the effects of sulfuric and other acids in the air and rain. provides some understanding of what is produced by a volcano.
    An interesting account may be found by searching for “Iceland volcano 1973”.
    It’s tiny compared to Yellowstone.

  5. I posted this on the previous article that had the buffalo video.

    “When you view the video note the activity at the 10 o’clock position of the video at the beginning. it is up on the foot of the mountain. It appears to be some kind of steam(?) or maybe an hydrology event. The snow is discolored and this maybe the reason the buffalo are on the move.”

  6. After the St Helens’ eruption some 2,300 miles away; Following winter Louisiana recorded 20+ measurable snowfalls vs two normally. A YSNP event would be 1K times greater.

  7. I read that this video is a few years old & that they animals r running from a predator.

    However I’m not dismissing the danger that Yellowstone presents. Worldwide I think there has been a significant increase in earthquakes & volcanic activity.

  8. Really, I hate to say this but all civilians would be done for. You can’t just think of the shock wave you have to think of the ash which shreds lungs, the chaos because people would go crazy, the food because its all going to be destroyed, and the economic collapse not mentioning all America’s hostile enemy’s who would indeed take the cataclysmic occurrence to their advantage of an invasion, nuclear attack (more realistic) etc.

    1. America’s hostile enemies? We have no real State enemies. usually when people say this they inevitably mean Russia and China, it seems like.

  9. You claim that people within five hundred miles would be dead. I can’t buy that as fact because there are variables involved. For instance it depends on which way the wind is blowing and in my case winds for the most part blow from west to east or south east and then from north to south depending on the time of the year. When Mount St. Helen’s blew I got ten inches of ash and yes had to clean it off my roof before it got wet. I believe more people will die from panic and being stuck on the major highways and interstates trying to run from this thing than those who sit it out. If they have plenty of WATER and foods, filtering mask, goggles and use common sense instead of panic people will survive. I by all guestimates live in the secondary ash zone in Idaho and I have already determined that I am staying right where I am at. I am 366 miles from yellow stone separated by mountains.

    1. You must also consider the initial shock wave through the ground and then all the aftershocks. The earthquakes triggered across the entire U.S. would be catastrophic. I have been in an 8.2 in Guam in 1993 and the ground was moving more than 6 feet high, bouncing cars upside down. That would be nothing compared to the Richter Scale reading that you would see where you live. The piroclastic wave and ash fallout would be the secondary effects of the eruption. Felt Mount Pinatubo in the Philippines long before the ash got to us in Subic Bay Naval Base in 1991.

      You are definately too close for survival. The mountains won’t stop this event from killing anyone from ground zero up to 600 miles from the blast.

  10. I think that all we can do is prepare; maybe make a little shelter with food, water, and other supplies. I have a shelter and I think I will live just fine if I am prepared. Yes this will be terrible but being 1,635 miles away from yellow stone can give me a little hope and if we move farther we could still have wifi and telephone connections making sure we can contact family and friends, also once it is all over and we know it’s safe we can go farther south getting into safer areas to where we could move out to other places. I’m very scared but I know if we don’t panic we can pull through guys, wishing you all the best of luck ❤️

    1. No matter what happens we will survive good luck every body and .May God be with us all

  11. The amount of ash being deposited would largely depend on the time of the year and the locations of the polar and sub-tropic jet streams and even El Nino. The ash wouldn’t reach as far south in the summer as it would in the winter nor as far east. How quickly the ash accumulated on the Rockies would also play a part as increasing the height of the mountains would have a direct and immediate effect on lower-level air flow and weather patterns.

    If, by some chance, the majority of the ash is deposited across Canada and further north, that area will experience a warming, not cooling, as the dark ash absorbs the heat of the sun instead of reflecting it back into space as the ice does. The result will be a rise in the ocean levels as the polar ice melts.

    The real question is would the event trigger a chain reaction along the fault lines along the west coast and central USA? If so, the desert southwest could once again become a great salt lake as the Gulf of California extends into Arizona and New Mexico. The Mississippi river valley could also be altered significantly.

  12. Honestly there are signs that something bad is coming. For sure, but listen we humans are dead and done for. Well on a religious standard i think these are signs of something bad coming. not just Yellowstone but something bigger. why do you think that there are alot of end of the world videos, (maybe to get famous, or just plain stupid people), but i think that humans know something bad is coming yellowstone will be like a small portion of what will be the end of the world. Now i do not believe this end of the world thing. But i do know something is coming quick. if it happens it happens. and on a non religious standard i think there are alot of signs as well. well if it does happen might as well shoot myself in the head and be over with it. lol life sucks. But you know if it happens it happens. there must be reason for it.

    1. Someone replied, “Well said.” But: “well if it does happen might as well shoot myself in the head and be over with it.” Not well said. The worse things get, the more important it is to do our best and help others however we can for as long as we can. And if we can’t help others in any way with any action or word, even just being there to be helped draws others around us to do more good than they might do otherwise. If we suffer, we can endure heroically, which heroism is perhaps the most helpful thing of all to do for others around us. If, no matter whatever happens, we refuse to do evil, and only do good, then (it certainly seems to me) our lives are ultimately well lived, and we will be worthy of the gift of life. Best wishes to everybody.

      1. If and when yellow stone does erupt we will survive god bless America no matter what happens we will due good luck to everyone and we all pray to God that yellow stone does not erupt

  13. Nit-pickers – – take a hike. Writer’s comments are global; no one knows what the dimensions of an explosion might be. Just too many unknown variables. Writer’s predictions are at least, within the range of plausibility.

    Key question: any way to survive a catastrophic event of this magnitude? If so, how? What are the considerations?

    Thanks (don)

  14. The destruction would wipe out the west coast, the ash would suffocate the earths atmosphere and block out the sun. The sun nor moon will rise for about 5 years, by then, most plant life (I would guess 75%) would be extinct unless the governments make plans to preserve them, many animal species would go extinct, that’s for sure. Many humans would die off. (All the undesirables would die off while corporate elite, mafia, presidential, and well prepared individuals)Watch a movie called “The Road” that would pretty much be how shit would go down. humanity would survive in the form of rape gangs, lone wanderers, and small communities around the few hundreds. After ten years, we would start to see military presences and scientists working on adapting new life, cultivating plants and laborers would take care of the few livestock remaining. (Chickens mainly because they are easy to raise as long as they aren’t diseased)

    The surest way to survive: Get guns and ammo, learn to maintain them, kill anyone evil, and work together to save humanity, food would be the biggest concern too…

    1. Sounds almost biblical…the sun darkened, the moon turned to blood, a third of the fish and men and plants and animals dying. Waters turning to poison. Doesn’t account for the great mountain falling into the sea, though. Oh, well. I suppose we can’t have everything. :P

      1. Oh, yes it does: when a volcano explodes, the volcano itself can collapse into a depression/caldera, and nearby mountain ranges can also collapse .Depends on what volcano goes off and how big the eruption is.

  15. What if there was a society during the dinosaur time? Empires and races rise and fall…

  16. Where and how bad depends on many things but, during the three known (assumed) major eruptions, most of the ash west of Yellowstone was stopped by the Sierras; eastward it extended from the Canadian border to the Gulf of Mexico, extending almost to the Mississippi. Look up “Yellowstone Ash Beds”.

  17. in short: if this event will happen we do not have any chance to survive and all this stuff that this page try selling to us are useless

  18. No, there will be a chance for survival as far as I can tell, if you live towards the eastern half of the country. The best bet would be to leave the US before it happens. The only tricky thing about that is that we do not have any idea when it will actually happen, and you can bet that as soon as the eruption occurs, travel will be shut down in the US with very few exceptions, such as military and governmental, and your chances of making it out on your own are slim to none.

    One question to pose would be, if this eruption occurs, will any countries in South America, Europe, Africa, or even Asia help evacuate the US? Logistically, financially, and socially, it is not in their best interest to do so, however I find it plausible that there may be some kind of organized evacuation attempt in the weeks/months/years after the eruption.

    Also, if there is no mass-evacuation of this kind, there will be massive land migrations of people. We could assume that many of them will attempt to head south into Mexico, with the remainder staying put or heading north into Canada and a decent percentage of those cramming themselves against the east coast of the US.

    With the recent activity in Yellowstone, I find myself becoming increasingly concerned with the matter. Once I and my fiance become more financially stable, we will likely move to Europe, for several reasons. This volcano seems like it will make it onto that list as well. I can only hope that we are far from it by the time it blows.

    1. Interesting discussion, but Europe is far from immune from the effects of volcanic destruction. Iceland is highly volcanic, as is the areas around Naples, Italy. Both regions are capable of supervolcanic eruptions.

      Out of the frying pan, into the fire?

      1. How do you think the economical collapse of the U.S. would effect Europe? Especially considering the country I live in (Norway), where all agriculture and most consumer goods is dependent on the EU supplying us. There are few self-sufficient states in the EU in terms of having everything necessary to maintain a controlled society.

  19. Super Volcanoes overall would not be greatly affected by wind. The shear force of the explosion and constant super eruption, when run in computer models, can push the ash cloud UP-WIND (that means towards the current direction of the wind) up to 500 miles. That means if the wind is blowing from west to east (as usual in the summer) the ash cloud can be blown from east to west up to 500 miles regardless of wind strength/jet stream. Think of an atomic explosion.. you ever seen one leaning?? or crooked? I haven’t. After the explosion has settled down then the winds and jet stream resume their push in the direction they are flowing and push the fall-out the direction of the flow. Current winds just direct how far out the ash will flow and in what direction.

    Look at the old ash beds.. some are way south and north and west but mostly east due to wind..

  20. I find it unfair that this probably won’t effect the criminals in Washington……to make it fair and if were all going to suffer from this massive blow, then I would be fine if they get it just as bad as we do. But that’s not what’s going to happen, they will get the first flight out of here, you know it I know it and they know it.

  21. This is a wake up call to every American out there. It is your duty to your children to store water,food,guns,ammo,and a source of heat for at least a month supply. The last thing I could handle is watching my son starve. I don’t want to be in a panic with thousands of others searching for water and food. I know you think what would a month supply do….well it will weed out the unprepared and give you and your children a fighting chance…..maybe that’s what all this jade helm 15 stuff is all about. There is something coming tho and you can feel it in your gut. Think about things you will need, everyday I do this….I store things for what ever is coming. I have gas masks I got online for $19.99 each. There never used army issued.i buy 25 year survival food by the buckets….you name it I store it. You can call me crazy but better to have it and look crazy than not and be one of the wondering sheep waiting for the slaughter.there will be no rule of law and you have to think this way. I don’t know what has lead me down this path of preparing for survival,but I’m not going to ignore the signs given to me. Wake up America it’s coming, I don’t know what but it’s coming. Oh yea get right with your creator who ever it may be.

  22. Yes, it’s coming. The interesting thing to me is that a lot of preparation seems to be localized. People in one area are stocking up on food, people in another area medical supplies, people in a third are all ready to bug out. These are unrelated people who apparently don’t even know each other, and yet they’re preparing in similar ways. It would be interesting to see a poll showing different areas of the country and what people are doing there in regards to preparation. (Hint*)

  23. Maybe nobody.
    It would depend largely, it seems, on the season and the strength of the jet this stream. And factors such as force and direction of the blast(s), atmospheric level at which the bulk of airborne debris settles, and whether it is the polar or subtropical jet stream that captures and pushes along the ash cloud.
    Cooling certainly would occur. In 1991 the Mt. Pinatubo eruption occurred in the middle of the Fires of Kuwait. The eruption caused global cooling for a couple years while the fires had just a regional impact. Neither was a significant event compared to what a Yellowstone eruption could be.

  24. No one c an predict what a super eruption from Yellowstone might be like good luck to everybody and pray that we survive it

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