We're U.S. volcano scientists remembering Mt. St. Helens' eruption. Ask Us Anything!

Say Rainier decides to blow its lid - what should I spend the next hour from that moment doing as a resident of Tacoma?

Hey theCheekyBastard - Great Question. I think as a resident of Tacoma, it's more important to think about what you should be doing NOW to mitigate the impacts of a future eruption. There are some great resources on Pierce County's "Active Volcano" web page where you can learn about Rainier/Tahoma's hazards and what you can do to get prepared for them (Which is quite a lot!)
https://www.bing.com/search?q=pierce+county+active+volcano+web+page&cvid=6fd66d8f389b443ca02a81b779848f0f&aqs=edge..69i57j0j69i11004.5871j0j1&FORM=ANAB01&PC=U531

Even though Mt. Rainier is a really big volcano, it's really not very explosive - much less so than Mt. St. Helens. It's biggest hazard is lahars, or volcanic bmudflows, so what your actual danger is from a Mt. Rainier eruption really depends where you are in Tacoma. If you're up on the hill, (like most of the city), you really don't have much immediate danger at all - but there will definitely be long-term impacts to any large enough to make it all the way to Tacoma - it would take a huge one to get that far, and it would cause long-term changes to the river valleys..

If you are down in the river valley, you'll want to know how to reach the safety of high ground, and how you're going to be alerted that there's something you need to evacuate going on. For Tacoma, there are outdoor warning sirens to warn about lahars, but a NOAA weather radio, and subscribing to PC Alerts (from Pierce County), will really help you know when you need to get up and go! you can find links and information about both those sources (and USGS's Volcano notification Service) at https://mil.wa.gov/alerts!

Hope this helps! - Brian

Even though Mt. Rainier is a really big volcano, it’s really not very explosive - much less so than Mt. St. Helens. It’s biggest hazard is lahars, or volcanic bmudflows, so what your actual danger is from a Mt. Rainier eruption really depends where you are in Tacoma. If you’re up on the hill, (like most of the city), you really don’t have much immediate danger at all - but there will definitely be long-term impacts to any large enough to make it all the way to Tacoma - it would take a huge one to get that far, and it would cause long-term changes to the river valleys..

Puyallup, Orting, etc, would be having a bad, bad time.

How accurate are the lahar maps from the USGS? I'm trying to determine how big of a threat it would pose to my neighborhood, which is in the valley, but not near the main flow on the maps.

The lahar maps from the USGS are very accurate - they're the standard you should do your planning by, and they've done even more recent modeling that supports them. Here's a video that sheds some light on the timing of those lahars in the zones: https://www.youtube.com/watch?v=RYTbfySHSxU

While their maps are excellent, the form you usually get to see them in isn't the most interactive - I recommend checking out Washington DNR's geology portal for an interactive version of the same maps, where you can type in an address and compare it to the maps. it's available at https;//geologyportal.dnr.wa.gov

(Unfortunately, it doesn't work well on mobile, but if you're at a computer I hghly recommend that site.
On the table of contents on the left when you open the page, uncheck "surface geology" then check "Volcanoes" and "Volcanic hazards" in the drop-down menu that shows up - and type in the address you want to know about.
-Brian

Wow, the lahar simulation video is very informative! And terrifying.

Glad it's informative - sorry to hear that it's terrifying. We hope that having a good understanding of the hazard will help you prepare to respond to it. While it looks like it's only a short time until lahar arrives (and it is), for reference, each year, all the students in the city of Orting practice walking their lahar evacuation routes, and they are all able to walk this distance within the time they need to - for some this is a distance of almost 2 miles.

The city of Puyallup has also done this drill a couple of times, and found the same results - Everyone CAN Walk to high ground in the time they have available after an alert - but the key is practice - know how you're going to be alerted, and know your evacuation routes, and practice them! You've got this!
-Brian

If you live in the Puyallup River Valley, get to high ground. If not, find a place with a view of Rainier and enjoy the show. (but prepare for ash if the wind is blowing toward you). --Larry

I live in the Pacific Northwest. If we have a major earthquake on the Cascadia Subduction Zone, could it set off one of our volcanoes? Or vice versa if one of our volcanoes erupts?

Good question, and thanks for asking! It's possible, but really unlikely. Looking at other large earthquakes and eruptions around the world, there usually needs to be magma high up in the volcano, and getting ready to erupt for the shaking from an earthquake to "trigger" an eruption.For Reference, our most recent Cascadia Subduction Zone earthquake (in 1700) did not trigger any eruptions of any of our 5 active volcanoes. SImilar stories? In 2004, the magnitude 9.4 Sumatra earthquake, in an area with far more frequently-erupting volcanoes than the pacific northwest didn't trigger any of them to erupt either; nor did the 2011 Tohoku earthquake in Japan.So historically, it's not really common.However, since we want to make sure you're prepared for all the hazards you could possibly face - a good idea is to make sure that whatever your plans for disasters are, they will work if other hazards occur, too! For instance, would your volcano plan work after an earthquake, or would the earthquake damage something that means you wouldn't be able to receive volcano alerts, or properly evacuate. If there was an earthquake, are you still ready for a flood? or Fire? or other far more common hazards? NOW, while things aren't happening *knocks on wood* is the best time to think about things like that, and make sure your evacuation and communication plans would still work if soomething was different than just one disaster at a time (earthquakes might not trigger volcanoes very frequently, but they do often cause landslides, tsunamis, and fires). And what about fiires or floods during Pandemics? Those are challenges we all had to think about during the past couple of years, that made things more complicated.I recommend reaching out to your local emergency management agency as a place to begin learning about the hazards in your area, and what you need to be prepared for them.Hope this helps!
-Brian (Edited post to add name)

Thankfully, no. Imagine trying to cope with a major earthquake AND volcanic eruptions (sounds like a movie plot straight out of Hollywood!). Volcanoes have their own magmatic systems and whether or not they erupt is based on what's happening locally, within that system. It's incredibly hard for an external event to trigger an eruption. Just look to the 2011 Tōhoku earthquake (Mw 9.0–9.1) as an example. The large earthquake didn't trigger eruptions from volcanoes in Japan (or elsewhere). - Liz

• As a very small child, I was mildly traumatized after seeing interviewed on TV the few folks who refused to evacuate and knowing afterward there was no way they could have survived. Why weren't they forced to leave?
• What caused its eruption/explosion to be so one-sided? Was that one-sidedness predicted or anticipated?
• Is Mt. St. Helens over its own "hot-spot" or does it share an area with Mt. Ranier & Mt. Hood?
• How likely is another mountain erupting in the Pacific NW during the next 25-50 years?
• What is the next, most likely place for an eruption in the lower 48 states?
• Do Vulcanologists/Seismologists have a way of measuring pressure beneath a mountain prior to obvious external indications of impending eruption? How early in the process of pressure building are seismic indicators useful?

A lot of great questions in here, thanks for asking! Will answer a couple, and save some for other experts (who will arrive around 11):- Washington has always been a "home rule" state, meaning the State government isn't allowed to force anyone to evacuate, no matter the hazard. in some areas, local officials can override that and force evacuations, but it depends on the area. To add to the complication though, while geologists monitoring the volcano knew it was potentially preparing for a larger eruption, forecasting exactly when, where, and how large an eruption will be (annd in which direction, precisely which hazards will accompany it, etc.) is still not an exact science. The observatories have gotten much better at it since 1980 from working with and on other voolcanoes around the world, but it's still tough to say exactly when something will happen, and that uncertainty really makes telling people to evacuate difficult. Imagine being told to leave your home, asking "for how long" and officials not having a solid answer. In volcanoes in unrest around the world, that time before an eruption could be days, but it could also be weeks, months, or even years - annd the volcano may not even end up erupting at all! (this happened with our own mt. Baker in 1975 - several months of unrest, no eruption!). So this uncertainty makes it really difficult.From my perspective in emergency management - I respect that people make their own decisions about whether to evacuuate or not, but the really important thing is to help people understand exactly what those hazards they might face are when their volcano erupts, so they can make a solid and informed decision for themself and their family.

- On St. Helens over a Hot Spot: All the volcanoes in the Ccascade Range in Washington, but also Oregon, Northern California, and British Columbia, are located along a subduction zone - where the plate of Juan De Fuca is subducting beneath the North American plate. Once that plate reaches a certain depth in earth's mantle, it releases water, which causes the mantle to melt, and that melt becomes Magma, and rises up through 30-40 miles of continental crust. This is a long and difficult journey, so it only ends up coming to the surface in several places, but it tennds to continue following those pathways for thousannds of years, since they become paths of least resistance of a sort, the easiest ways for magna to reach the surfacee, so those vents where magma repetetively reaches the surface are called volcanoes. This is why if you look at a map of volcanoes in the Pacific northwest, you'll see that most of the volcanoes are roughly parallel to the subducting pate, and about the same distance inland from it: https://www.usgs.gov/observatories/cvo (<there's a good map of the volcano locations.) Mt. St. Helens is a bit offset from the others, but it's magma still comes from the same subduction zone as the other volcanoes, just takes a different journey to reach the surface!

...hope that helps for a couple fo the questions - and I'm going to let others answer some of the other questions on here!-Brian

through 300-40 miles

Can I just ask for clarification on what's presumably a typo -- should that be 30-40 miles? Thanks.

Yup! that's definitely a tyypo... Wow, the double Y was not intentional, but I'm leaving it in so you can see what this unfamiliar keyboard is doing to me today!! Will try to catch more of them though, thanks for the heads up! (And editing above, in case people only see that!)
-Brian

Great questions! I'll tag-team on the responses with u/WaQuakePrepare.

Q: What caused its eruption/explosion to be so one-sided? Was that one-sidedness predicted or anticipated?

A: For 2 months leading up to the May 18, 1980 eruption of Mount St. Helens, a bulge was forming on the north flank of the volcano. It became "gravitationally unstable" and failed, generating a huge landslide. The landslide "uncorked" the volcano to generate a northward blast. At the time, scientists were very concerned about the landslide but didn't anticipate the ferocity of the lateral blast. - Liz

Q: How likely is another mountain erupting in the Pacific NW during the next 25-50 years?

A: If you look back at eruptions in the Cascades over the past 4,000 years, they occur at an average rate of 1-2 per century. So chances are, if you live in the PNW for a lifetime (reaching 100 yrs of age) you will have experienced 1-2 eruptions. When the next one will occur, we can't say. Mount St. Helens went from a quiet volcano to producing a catastrophic eruption in 1980 with only 2 months of warning, which is why we talk so much about being prepared for the next eruption. At CVO, we install monitoring equipment on volcanoes to help give us early warnings of unrest, and we'll pass that information along to you. - Liz

Re: Pressure. Certainly earthquakes are giving a sense of an overall change in pressure in the plumbing system, but it is hard to model that to get an absolute pressure change. You can model the deformation of the volcano to get a change in pressure, but it still isn't clear how much pressure is required to start an eruption.

Re: Seismic precursors. Every volcano is different. Mount St. Helens had about 7 days of lead up time (strong seismic precursors) before the first explosions in 1980 and 2004. Kilauea and Mauna Loa had precursory seismic sequences that last from months to years.

--Wes

How scared should I be of the Yellowstone Caldera, and if it was truly about to erupt, can we/you lovely people do anything to help humanity?

Are there any good movies about volcanoes? If not, what's the least ridiculous?

You shouldn't be scared of Yellowstone - at all! It's very unlikely it will erupt during the lifetime of any single person alive today. When (if) it eventually erupts again, it's more likely to be a mild explosive event followed by a large and long-lived lava flow, impacting only the area inside the National Park.

Movies: the new Volcano of Love is pretty good, but the Krafts were a bit too risky for the taste of many volcanologists! Otherwise, Dante's Peak still holds strong, even with its inaccuracies! - Wendy

On the subject of Volcano Movies (Goodness to be determined), last year we live-tweeted "Dante's Peak." This year, we're planning to Live-Tweet the other 1997 movie: "Volcano!"Here are some more details coming straight to you from the twitular bird-app.

https://twitter.com/waShakeOut/status/1656699119417827331

It will be May 31st from 6:30-8:30 p.m. - follow and/or Tweet along with #VolcanoReady!

-Brian

Regarding Dante’s Peak….thoughts on the old lady getting out of the boat in the lava lake? 🤷🏻‍♂️

And what about that historically accurate competitor Volcano starring Tommy Lee Jones and John Carroll Lynch who saved that train conductor by throwing him while his legs were melting…..you will not be forgotten 🪦

This is Mike. Now that you mention it, those two movies really had it out for people's legs...

That acid lake scene in Dante's Peak, well, that was a bit extreme. There can be an increase in acidity of some water areas, but not whole lakes, and not to the point that it is so concentrated it would dissolve you. At worst it might be like wading through orange juice.

What is your favorite volcano? Why?

Like Mike's answer, I'm a big fan of a lesser-known volcano. Newberry Volcano in central Oregon is the bee's knees. It's very large (though not tall) and looms over the city of Bend, Oregon. It's got everything....Hawaiian-style erupted cinder cones and long lava flows, lava tubes, a young (~1300 year old) obsidian lava flow, explosive ash deposits, and hot springs! But please don't tell Kīlauea I said this..... - Wendy

This is Mike. My favorite is Medicine Lake Volcano -- probably the coolest volcano you've never heard of. It's to the NE of Shasta by about 35 miles. It's a low shield, not a pointy stratovolcano. Has lava tubes (and Lava Beds National Monument!), obsidian flows, a gorgeous lake in the summit caldera, and is just all around beautiful and little known. It's not a showoff like Shasta.

Mount Shasta because it is nice to ski at about this time of year. 7k of smooth skiing and no crevasses. Plus there is Yak's (not an endorsement).

--Wes

Can I pick two? Mount St. Helens is my favorite stratovolcano, mainly because I spend a lot of time there and it feels like it's MINE. And Kīlauea, of course, with its lava flows (2018) and the lava lake. Pele is currently taking a break, but I know she will be back. - Liz

There are so many. Kinda like asking which is your favorite child. -- Jon

I visited Kīlauea last year and it was probably the most memorable night of my life.

We came into the park late at night, probably around midnight, walked down the old Desolation Rd, took that right hand turn down the path... and the whole plateau fell into a void. And at the far side, there she was - Mme. Pele doing her thing down in Halema'uma'u. You could see the orange and red glow in the cracks breaking the lava crust on the lake as they slowly meandered across the surface, sparkling as occasional drops of water fell in, while the tunnel feeding the lake poured out millions of tons of white hot liquid basalt, kicking out heat waves so intense you could hear them just by looking at them from our perch a couple miles away.

Rain was absolutely soaking the Volcano Village, 200' below, but the edge of the caldera was barely above the cloud line, and the rain kept trying to send little wisps of clouds into the caldera where they would get blown apart because of the rising heat. The sky above was crystal clear, with Mauna Loa looming in the distance and the Big Dipper draping her southern shoulder. And then - the full moon came charging up past the trees behind us, casting a goddamn full-color MOONBOW which arc'd high over Kīlauea Crater and terminated IN the lava lake.

It was like Hawaii was showing off. I've never seen anything like it.

https://i.imgur.com/9SZLqnV.jpg https://i.imgur.com/U4meRhr.jpg

Anyway, I know research is one thing, and academic life is another, but all of you have spent time in places like this and, oh man - life well spent!

I'm still blown away just thinking about it. If I'd experienced this when I was younger, I'd probably have given serious thought to moving to Hawaii to study volcanoes.

How did you all decide to go into this field? And was it just coincidence that caused Kilauea and Mauna Loa to shut down at the same time last year? And why did Kilauea go off a couple weeks later?

Dang, you had quite the night! Thanks for sharing your poetic experience with us...I could envision it as if I were there! I landed on volcanology because of watching volcano documentaries on TV while in geology undergrad. Geology is such a slow process, except for natural hazards, and volcanoes create new and fertile lands (after the decimate everything) - it was the death and rebirth cycle that pulled me in (I have my woo-woo tendencies). Plus, while watching the documentaries and seeing scientists being interviewed, I wondered..."where are all the women?" We're growing in number! - Wendy

For me it was a bit of coincidence. 40 years ago as a grad student I got involved in a project at Mount St. Helens and it blossomed from there. Been to volcanoes all over the world, and although exciting emotions have had to be tempered as I've seen both beauty and tragedy. But its been one heck of a career that I would not trade for anything. I'll let one of my colleagues chime in about Kilauea and Mauna Loa. -- Jon

Thanks for sharing your story and photo! Yeah, same here and a story i've heard from a number of others - I visited and climbed St. Helens when I was young - learned all the stories about it's eruption, it's history, it's place in the culture of the area - and I was just hooked . The fascination has only grown with every volcano I've been lucky enough to visit! (And there's more on Kilauea below, but thanks for sharing your experience!)
-Brian

It seems at the observatory that most people are volcano junkies...they all just find different ways to approach the problem. In my case, the school I did my undergraduate degree at also had a seismic network, so there were lots of opportunities to grow in that area.

Kilauea and Mauna Loa have independent magma systems, but inflation on one can make it harder for the other to erupt. So its not coincidence, but there is a lot of science left to do to be able to add this kind of information into forecasts.

​

--Wes

At what point in your education/career do you decide to specialize in volcanoes? Do you start towards that in college/grad school or does that more often occur later?

Wendy here. Thanks for the question. You will get many different answers here. I only discovered geology was a career in my early 20s on my way toward a different degree at a school that didn't offer a geology major. After a professional career that left me unfulfilled, I went back to school in my (very) late 20s for 2nd undergrad in geology. It was there I realized I wanted to pursue volcanology as a career.

Was it tough changing careers/going back to school that "late"?

Nope. It was great, because I finally realized what I wanted to do and I just put my head down and did it! Plus...VOLCANOES! They're hot. - Wendy

I went back for geology degrees "late" as well. I loved it! It felt like I was making my own choices and now I'm doing what I wanted. It's never too late.... - Liz

Great question, thanks!
I'd say the time you start to think about really specializing in volcanoes is usually Graduate School - going for a Master's Degree or PhD. These are the times where you conduct research on a topic, which really allows you to become an expert on a specialized area of that research. But you can be thinking about that specilaization for a long time. I studied geology for my Bachleors, but realized I really wanted to learn more about volcanoes, so searched for a program where I'd be able to research them for a Master's.
But everyone's Story of how they got here is a little different, so I'm sure other volcanologists on this AMA will have different stories. Hope this helps, though!
-Brian

How likely is Mt Hood to wake up any time soon?

Also, how fucked is the town of Hood River, and the gorge in general, if Mt Hood ever decides to do something drastic.

Over the past 20,000 years or so, Mount Hood has had three eruptive periods, roughly 20,000, 2,000, and 200 years ago in round numbers. Mount Hood is not a highly explosive volcano, rather it tends to erupt lava domes much like what we saw at Mount St. Helens in the 1980s and again in 2004. It has shed some large volcanic mudflows that have traveled down the Hood, White, and Sandy River valleys. The current geometry of the mountain is such that the next eruption will likely occur on the south side (which is where the focus of activity has been the past few thousand years). One of the most concerning aspects of a future eruption will be the possibility of pyroclastic flows related to collapses of new lava dome growth, and they could flow down toward Government Camp. So, will Hood wake up anytime soon? Hard to say. Just like any of our other Cascades volcanoes, it has been active over the past few thousands of years, but currently shows no signs of unusual activity. It does have a fairly consistent habit of minor earthquakes and minor earthquake swarms, but these are part of its background chatter and not out of the ordinary.

When my kids talk about the potential for an eruption of Mt. Rainier (Tahoma), the one thing they always ask is how loud will it be?

Probably not very loud at all. You might hear the rumbling of earthquakes or of boulders rolling down the river in lahars. At Mount St. Helens in 1980 some people heard a sonic boom when the lateral blast occurred. But we don't expect a lateral blast at Rainier. It is not nearly as explosive as St. Helens. Larry

What should I do with the bottle of ash my grandfather collected from the eruption?

If you want to give it away, offer it to your local school. The May 18, 1980 eruption of Mount St. Helens changed our world (https://pubs.er.usgs.gov/publication/fs20203031) and the story should continue to be told. - Liz

I was 6 years old when Mount St. Helens erupted, and I was living in Spokane. And it was so cool seeing the entire city covered with ash for the next few weeks. It was one of my favorite childhood memories, and I feel bad for other kids who never got to experience something like that. Do any of you have any personal favorite experiences with volcanoes like that?

When I worked in Hawaii, I always enjoyed getting Thai food and watching the Halemaumau lava lake glow at night from the overlook. Thai food was the only good thing to eat in Volcano at the time...

--Wes

Hi Mariojlanza. I'm an ash specialist but unfortunately have never experienced ash as you have. I was flying around the Mount St. Helens Crater in 2004 when on of the steam eruptions started. That was one of my high points. Another high point (literally) was sitting at 5,300 meters elevation in the Andes, watching Sabancaya send up plumes every 10 minutes or so in 2018. --Larry

How many volcanologists would you say there are in the world? If Helens were to happen today, would y'all be flying in from around the world to see it?

There are probably a few thousand in the world...depending on how you define "volcanologist." We're considering people with graduate degrees in a related science and work directly in the field. - Wendy

This is Mike. Eruptions definitely attract scientists form around the world -- lots of volcanologists have gone to Iceland to look at the recent eruptions on the Reykjanes Peninsula, for example. Generally these folks aren't going to be looky-loos, but rather to do some sort of experiment, or test an idea, where you need an active eruption. Although to be fair, some do go as volcano tourists. If I had the means I certainly would!

Any eruption of MSH would be a big deal and thus we would bring in our colleagues from other observatories to help out for sure.

--Wes

What would you guys rank as the most dangerous or highest risk volcano in the continental US?

NOT YELLOWSTONE

--Wes

The most dangerous is probably Mount Rainier because of its potential for large lahars (without eruptions) and the number of people living in valleys that could be impacted by those lahars.

--Wes

What's the best documentary on the mount St Helens eruption for those of us who'd like to understand it better?

I can't name any documentaries off the top of my head, but highly recommend visiting the Mt. St. Helens National Volcanic monument if you ever have an opportunity (and hope for good clear weather). The visitor centers are excellent (including a couple of short documentary-style videos about the eruption), and are really the best way to fully understand all the aspects of what happened on May 18th, and in the lead-up to the eruption.
--Brian

Would you like to hear from scientists in their own words? The USGS has a great video of scientists talking about how they responded to the 1980 eruption of Mount St. Helens: https://www.usgs.gov/media/videos/may-18-1980-mount-st-helens-eruption-stories-usgs-scientists

There's a cool one on Disney+ that features at least one photographer in a helicopter while it was erupting.

As an aside: The Washington National Guard had helicopters nearby doing training and when the eruption started the pilots headed to the volcano to rescue people. You can read more about it in this Twitter thread from 2021. -- Steven

There are a few books you might want to check out, since recent documentaries are few and far between. "Volcano Cowboys" tells the story nicely. A more recent one is just called "Eruption," and "In the Path of Destruction" was written by a USGS scientist who was there in 1980 and who collected lots of eyewitness reports of the event.

What seemingly minor seismic activity or volcano activity would you make you go "oh, that's bad,"?

This is Mike. It would depend on the volcano. Volcanoes are like people -- they have personalities. Some are quiet and relaxed, and others are always making noise.
A swarm of, say, a few hundred earthquakes at Baker would be noteworthy, since it is usually quiet. But a few hundred earthquakes at Yellowstone? That's a Tuesday. No big deal. Happens all the time.

Pro tip: Don't go to a geodesist for your seismic information.

--Wes

Seismology is just high-rate geodesy.

-- Mike

A unheralded lahar like the Electron Mudflow ~500 years ago....otherwise either tremor or shallow long period earthquakes would get my attention.

--Wes

I live in Portland! Folks say that when we get “the big one”, the Willamette River will basically be on fire from all of the stored oil and chemicals along the banks in Portland. My husband works on the West side but we live on the East side. Is it silly to keep an inflatable kayak at his work just in case he is there when it happens? I told him to put it before the falls in Oregon City to get across the river in case the bridges fail. I come from Hurricane country so this is all new to me. Thanks for doing this IAmA!

Interesting....a Nomex kayak, you say?! And yes! Keep a kayak at your work. I used to live on the opposite side of Columbia River from my office at the Cascades Volcano Observatory, and you better believe I was eyeing the canoe that hangs in the warehouse! Plus, you can use that kayak on days like today in the PNW when the sun's out and you don't want to be behind a desk anymore! - Wendy

My middle school daughter wants me to ask, “what chemical chain reaction causes an eruption?”

I told her I don’t think it’s a chemical reaction more than a physical reaction, but I could be wrong.

Hi prstele01. Volcanic eruptions are caused by the heat of magma and the pressure of magmatic gases. But there are some chemical reactions involved. For example, magmatic gas is dissolved in magma, like carbon dioxide is dissolved in a soft drink. It comes out of solution as the pressure drops, causing the magma to grow bubbles that expand and break the magma apart. The pieces between the bubbles are the volcanic ash. --Larry

Where and when do you think the next earth changing volcanic eruption will take place?

Hunga Tunga (not spelled correctly) happened last year. That caused a ton of water vapor to eject into the high atmosphere. How is that changing the planet?

Hi Farva85. I know of a couple papers that predicted the Hunga eruption would warm the planet slightly because of water vapor injected into the stratosphere. But the predicted warming was just a fraction of a degree. I am not aware of measurements yet that confirm the prediction. It was pretty small in any case. Most big eruptions have a cooling effect because SO2 aerosols reflect the sun's heat back into space. Pinatubo for example cooled the planet by about 1 degree Celsius for a couple of years. --Larry

Where were you May 18th 1980? What do you remember about the eruption, and did that ignite your interest in Volcano Science?

I was a college student in Geology, coming home from a field trip. It was event of a lifetime for most of us geologists. When I arrived at the Cascades Volcano Observatory, I met several people who narrowly escaped death. It taught me that volcanoes are not to be messed with, even if you think they're cool. Larry

This is Mike. I was a kid living in central California -- totally captivated by the news of the eruption. And realizing that there were volcanoes in my neck of the woods, namely Lassen and Shasta. I think that event, and then going exploring at California's volcanoes, really did set me on my current path.

I grew up not too far from where Wes grew up. But I don't think he was alive when St. Helens erupted in 1980. Pff. Whippersnapper...

I had just graduated from college with a degree in geology a month prior, and was living in Chicago. So, other than what I saw in newspapers and on TV, I had little clue what was going on. By happenstance, I was headed to grad school at Penn State later that fall, and my advisor there was a scientist intimately involved in studying aspects of the eruption. He got me involved in a project at Mount St. Helens in summer 1981, and I have been here ever since. -- Jon

What are the risks of the Newberry Caldera near Bend, Or?

Newberry is interesting because it can do lots of different things depending on where the eruption is. A eruption in the caldera could create plenty of ash with lava flows confined to the caldera. If it erupts outside of the caldera, it would probably be basalt in composition and have the ability to create cinder cones and lava flows. It is a Very High Threat Volcano, so all of the ingredients have been present for recent eruptions, but or monitoring network there is good so I don't expect anything to sneak up on us.

--Wes

The main things to worry about from Newberry are lava flows crossing U.S. 97 and blocking the Deschutes River. Flooding down Paulina Creek and perhaps on the Deschutes River (if a blockage were abruptly overtopped) would be of concern. Some cinder cones erupt off and on for months or years, so there would be chronic disruption in the area. --Larry

I’m heading to Pereira Colombia in the next few days and staying near Nevado Del Ruiz which has been raised to orange status. Should I be concerned? In 1985 it killed a lot of people, but the death toll seemed to be primarily due to poor emergency response.

Good question - Any time you're travelling near a volcano, it's important to know how you'll get alerted if something changes or becomes dangerous. As a result of the tragic 1985 eruption, the Servicio Geologico Colombiana is watching Nevado Del Ruiz very closely (we've worked with them on several binational exchanges so we can learn from them, and ensure that type of event doesn't happen here from our snow-covered volcanoes, too!). As a result, they're going to be the best source for info on the volcano,, and safety recommendations.(https://www.sgc.gov.co/)

Whether you're there, or here, if areas around the volcano are closed, or part of an exclusion zone, please understand that this is for your safety - because there are a huge number of unpredictable hazards that can happen within that area with no notice while a volcano is in an elevated state of unrest.
Besides that, it's a beatiful area full of great people, so hope you enjoy your trip!
-Brian

You can stay up-to-date about what's happening by checking the Colombian Geological Survey webpage: https://www.sgc.gov.co/. It's really important for travelers to stay current on what's happening and know what to do. - Liz

As a prospector/ rockhound, have any of you come across any curious rocks or minerals that weren't easily explained? Also, what are some of the legalities of collecting specimens from around a volcano?

Good question! There are a ton of natural processes that carry rocks far from their origin (glaciers, rivers, etc), but one of my favorites is when people pick up a rock somewhere then later decide they don't want it so they just leave it somewhere that is far from, or maybe even way uphill from where it should be. Good way to temporarily confuse a geologist! (Though they usually know to look for more in the area)..

If you want a fun story about this, check out the story of the great Diamond Hoax, in 1872. it ended up taking a geologist to look at the area and say: "Something's not right here..."
https://www.smithsonianmag.com/history/the-great-diamond-hoax-of-1872-2630188/
-Brian

I spent fifteen summer vacations in Yellowstone as a kid and for years my greatest fear was a vent opening under our tent/trailer overnight. How likely is a sudden appearance of a vent in an active area like Yellowstone?

These things don't happen suddenly, but new thermal areas can show up in areas within the National Park or new features can form within existing thermal areas. It takes years for new thermal areas to develop - a few years ago a Yellowstone Volcano Observatory scientist discovered one (read about it here: https://www.usgs.gov/observatories/yvo/news/newly-discovered-not-newly-formed-thermal-areas-yellowstone). New features within thermal areas can form more quickly. In 2014 a road that traverses the Lower Geyser Basin became so hot that it began to melt (read about it here: https://www.usgs.gov/observatories/yvo/news/melting-roads-yellowstone-national-park). - Wendy

Is your office pretty explosive? Or maybe a little dormant?

The weather is amazing here in the PNW (sunny and warm for a change) so everyone is out doing fieldwork. Well, almost everyone (sigh). I guess we've evacuated the building and are running toward danger. Typical behavior for volcanologists. -Liz

"The sun is shining and we got a geothermal vent spewing more toxic gasses than usual, who wants to go on a field trip?! Liz...Liz, put your hand down, you drew the short straw, you have to deal with the weirdos on the internet. Now, everyone else, grab your asbestos suits and load up!"

Ah shucks, that's what you always say. I'll put on my asbestos suit anyway and keep answering questions. - Liz

How much energy was released when it detonated?

tons...megatons

--Wes

Do we need to worry about Mt Shasta erupting.. I've heard it's an active volcano. If it did how much of an area could impact?

Mount Shasta is one of the more active volcanoes in the Cascades. But it hasn't produced a big explosive eruption in more than 10,000 years. Most likely hazards are lahars coming down stream valleys, and lava flows that could move across transportation routes, or into occupied areas. --Larry

The past two summers being dry with low snowpacks created a bunch of debris flows in the Whitney Creek and Mud Creek drainages. Certainly something to think about if you are recreating in the creeks around Shasta. Heres to hoping that a healthy snowpack up there keeps the debris flows this summer to a minimum.

--Wes

What are some of the most pivotal volcanic eruptions in terms of advancing volcano science?

This is Mike. St. Helens 1980 has to be on that list. So much was learned from the buildup, the event, and also the 6 years of subsequent eruptions (which volcanologists learned to accurately predict!). The 1983-2018 eruption of Kilauea was also important. Kilauea has long been a testing ground for volcano monitoring and research.

The big eruptions that happen when we have new technology have all spurred new science. Mount St. Helens is still the touchstone eruption for advancing our knowledge. Pinatubo (1991) showed us the importance of giant umbrella clouds and long-term resedimentation from lahars. The Hunga eruption last year showed us how eruptions can (occasionally) create global tsunamis and shock waves, and send plumes higher than most of us thought possible. --Larry

Okay so growing up- All of you guys thought volcanos were the coolest thing ever as kids, right?

There are people who don't think that?
-brian

Nope...I was clueless. I lived in the southeast. I did enjoy lightning storms and hurricanes though. - Wendy

Correct.

--Wes

For me, volcanoes were an acquired taste. - Liz

This is Mike. Yep. Still do.

Does the moon cause a volcano to happen faster than it would, without the presence of the moon?

Interesting question. The moon causes earthtides, and one of our former geophysicists looked into potential causality rather extensively. He was unable to find any evidence for a correlation. -- Jon

What is the level of concern for locations like Yellowstone and Mammoth Lakes in California? Are these hot spots like the Hawaiian islands or are they more like dormant locations of heat that are slowly cooling? I have read sources that seem to disagree with each other on this.

If only I could display a venn diagram of volcano types and magma sources.

Yellowstone & Hawaii = hot spots

Yellowstone & Mammoth (really Long Valley) = caldera volcanoes

Both Yellowstone and Mammoth contain magma storage regions that are kind of like a sponge - they soak up magma as it rises from the mantle through the crust. Some magma gets caught by the "sponge" and sits there to crystalize - a bit of liquid is left behind. When that liquid collects into a large enough amount (maybe 50%), it is considered eruptable, but that doesn't mean an eruption will occur. Based on science, both Yellowstone and Long Valley only have a small fraction of melt (between 5-20% maybe...). However, the tap of magma feeding the storage region at Long Valley is probably a trickle compared to a hotspot.

Now hot spots - Yellowstone and Hawaii are both fed by hotspots. But Yellowstone's hot spot is in the middle of a continent and the continental crust is THICK and made of rocks stubbornly resilient rocks and minerals. Hawaii is in the middle of an ocean, and oceanic crust is pretty thin and weak (less silica more iron). So, Hawaii's hotspot is voluminous and effective at supplying magma to the volcanoes that reside above the hotspot's apex. Magma is stored in an interconnected network of storage regions (so we think) at Hawaiian volcanoes, but there's WAY more liquid than at Yellowstone, which is why Kīlauea is considered one of the most active volcanoes on the planet. Interestingly, there's an experiment happening right now at Kīlauea to create a subsurface image of the volcano's plumbing system. We will know much more about what it's like once the results come in. Read more about it here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-imaging-underground-kilaueas-summit - Wendy

Has there been much growth in the dome in the last 15 years?

Follow up: What is the expectation with future growth events? Is it likely that the dome will eventually fill the entire hole giving us a new peak? How long would that take? Decades? Centuries?

Mount St. Helens went through two periods of dome growth, in 1980-86 and 2004-08. Lava hasn't erupted since early 2008. Interesting that the lava domes in the crater of Mount St. Helens are slowly contracting as the domes cool and settle. - Liz

One good way to understand what the future activity might be is to look at other similar volcanoes around the world. There are a couple of good ones, but Bezymianny, Russia might be the best. That volcano had a similar eruption to MSH in 1956. It is still building a dome that has almost entirely filled the crater back up. Now, comparing Bezy to MSH, Bezy has been much more voluminous in its dome building thus far (faster building). So depending on future events at MSH, it may take a few more decades or even longer to get the entire cone rebuilt.

--Wes

When thinking about Mt. St Helens, Krakatoa, Pompeii where these were fairly sizable and significant eruptions, what are the best ways that seismologists can predict for future eruptions? I know people always talk about Yellowstone to be the next "big one" but what are the actual chances and concerns for another catastrophic eruption globally and what would the impacts realistically be?

This is Mike. Yellowstone is definitely not the "next big one" -- seismologists have imaged the magma chamber, and it is mostly solid. So the Yellowstone rumors are more about clickbait and legend than anything else. But there are plenty of volcanoes like that around the world and that are much more likely to erupt in a big way. Typically, we get an eruption that has the potential to have a major regional impact every 500-1000 years -- those are about an order of magnitude smaller than the major Yellowstone explosions, for context, but are bigger that the Pompeii and St. Helens eruptions. A Mount St. Helens sized event typically happens every few decades. The last of the bigger style of event -- larger than St. Helens but smaller than Yellowstone -- was Tambora (Indonesia) in 1815. Certainly something that size happening today would be a global event. As for how that can be predicted, it's all about monitoring data. Only about 35% of above-sea-level volcanoes worldwide are monitored by ground-based equipment. With monitoring data, we can see unrest that might lead to eruption. Without monitoring data...well, that's when you get taken by surprise. Satellite data can fill some of those gaps (looking at gas emissions and ground deformation), but right now, the only way to detect earthquakes is with a ground-based instrument.

What's your favorite volcano-related disaster movie? Or your least favorite?

This is Mike. Not sure I have a favorite. Most are pretty bad. If you're going to force me to choose, I'd say Dante's Peak. Only because I've been told that I look like Pierce Brosnan and I do push ups every morning until my arms give out.

There are lots of bad ones. If you want a laugh, check out "When Time Ran Out" -- from 1980. Quite the cast, including Paul Newman, Bill Holden, Pat Morita, Ernest Borgnine, Red Buttons, Burgess Meredith, and more. It is terrible. As in, so bad it's funny. Paul Newman apparently said it was the only movie he regretted making, but he used the proceeds to found Newman's Own. So there's that.

IRL, I want the holographic 3d display from Supervolcano. :) -EMB

YES! Emily, you read my mind. -Wendy

Well, not sure if it's a "Favorite" but we are going to be watching and live-Tweeting the 1997 movie "Volcano" on May 31st! We did Dante's peakk last year which I have a sneaking suspicion is a bit more accurate...
Here's some more information about that event! you're welcome to join! https://twitter.com/waShakeOut/status/1656699119417827331

As a geologist studying at Montana State University, I’m wondering what pathways and career choices you took to end up in volcanics. What does it take to end up at the Cascade Volcano Observatory?

This is Mike. I would say networking and luck were what helped me. I got to know some of the staff at the observatory when I was a student. That meant I was a "known" (for better or worse) in case a job did come up. That's the "networking" part. The "luck" part was that a job did come up right as I was about to graduate. But I did my best to put myself in a situation where I could take advantage of the luck.

What do you think of the theory that there were Bigfoot / Sasquatch living around the volcano before it erupted?

Is there any reason to think this is plausible in this particular environment?

The area around Mount St. Helens was well trod by hunters for many decades prior to the 1980 eruption. Pretty sure they would have had a Sasquatch recipe before the eruption. -- Jon

I remember living in the state of Georgia, and we had that grey dust all over the car. Was some infinitesimal part of that cremated people?

This is Mike. We can at least tell you that whatever dust was on your car was not from St. Helens. No ash from St. Helens made it to Georgia. Anyway, most bodies were actually recovered after May 18, 1980.

If you lived downwind from a crematorium in 1980, though, chances are that dust was at least some proportion of cremated people. Soylant Gray, I guess?

Here are a few more questions ...

What would be your dream volcano project to work on if time and money were no object?

I would love to hear more from the panelists about their feelings on the duality - the awe versus the tragic - of volcanoes. It has been touched on briefly in comments, but I find that so fascinating and am particularly interested in how they message that.

This is Mike. Many of us were in New Zealand in Jan/Feb for an international volcano conference. And there was a lot of discussion among the local volcanologists about the White Island (Whakaari) disaster of 2019. The New Zealand volcanologists got very emotional. Some had lost friends who were working as guides on that day. It was sobering, since we can so easily get caught up in the awe.

Hi Zestyclose_Wrap3627. What a great question! We volcanologists love eruptions but don't want people to die in the ones we study. My dream would be to have a big eruption in a remote area where no one lived but could be watched by state-of-the-art monitoring methods, and produced never-before-seen phenomena that we could examine. The 2022 Tonga eruption was close to that. Seismologist may lament the lack of close seismoemeters, but we plume specialists have enjoyed a whole generation of satellites that can see stuff with unprecedented resolution. --Larry

Really good question - as the Volcano Emergency maager on here, I'd say installing lahar warning systems at all the cascades volcanoes, and a fully-funded outreach cammpaign to help people understand exactly what the hazards are from those lahars, their evacuation routes, the limitations of sirens, installing even more accessible alerting technology, while building trails in commnunities that make evacuation routes easier. ....That's all one project if your write the grant application in the right way :-)

As for the duality of awe vs. tragedy of volcanoes, this is a really important balance we have to strike, especially when going out to talk to people about their hazards (not just volcanoes, but earthquakes and tsunamis are a similar situation for us). We try to strike a "scare and prepare" balance in everything we share - it's critical that people understand the hazards, and respect the potential magnitude of it's impact on their lives - but don't become overwhelmed by the size to the point where they are unwilling to do anything. It's true that these are incredibly powerful forces of nature - but it's also true that people are not powerless in the face of them, and there are so many steps people, neighborhoods, communities, and governments at all levels can take to minimize their impacts when they do eventually happen.
-Brian

First of all, thanks for all that you do all do! I see a lot of USGS monitoring of Mount Rainier and Mount St Helens but it doesn't seem like there's as much monitoring or concern about Mount Hood?

And in the event of a mega thrust fault generated tsunami, how far up the Columbia River could a tsunami travel? I was unable to find Hazard maps for this.

Wah? Mount Hood has 11 stations within 12 miles with two more in the works. Mount St. Helens has a good network because it is most likely the next volcano in the Cascades to erupt and Mount Rainier has an awesome network because to the Rainier Lahar Detection System. But Hood's network is solid...

--Wes

Thank you! I am very familiar with kilauea's history and potental activity but less so with my new home in the PNW. Is it safe to assume that the warning signs preceding an eruption at hood would be similar to Kilauea? larger earthquakes as the magma chamber refilled? are there tilt meters and GPS monitoring on Hood? I couldn't find any USGS webcams for Hood like there are for Mount St Helens and kilauea. Although there are a lot of webcams from the ski resort on the south flank.

Mt. hood, like many other volcanoes in the cascades is heavily monitored with seismometers and (Wes feel free to hop in again and add more about the network at Mt. Hood, but it's at least seismic and GPS). Since hood hasn't erupted in a while, there will likely be earthquakes that move upward through the edifice as magma moves close to the surface, which seismometers will be able to detect. The best way for you to remain informed of this activity is to Sign up for USGS' Volcano notification service - they'll send an Information Statement if anything looks unusual about mt. hood (or any other cascades volcanoes), and if it appears to be potentially moving towards eruption might raise the alert level from Normal to Advisory, Watch, or Warning. You can subscribe to this free service here: https://volcanoes.usgs.gov/vns2/
-Brian

Hi BCS7. Tsunamis generally don't travel very far up river valleys. If I find a hazard map on this I'll post it. But I suspect there isn't one. Regarding Mount Hood, we do have a network of sesmic stations around that volcano. Every few years it produces a small swarm of earthquakes, usually below Mount Hood Meadows, with magnitudes up to around 2. But they have always died back down. Last eruption was in the 1700s. The last one before that one was several thousand years ago. So it doesn't erupt as often as St. Helens, or Rainier. --Larry

On the tsunami modeling part of the question, there has been some tsuunami modeling done, but its currently not in a very accessible format - Still you're welcome to check it out!
https://www.oregongeology.org/pubs/sp/SP-51/SP-51_report.pdf

Our Department of Natural Resources and Oregons Department of Geology and mineral Industries are looking into creating better maps, so hopefully those will be available soon!

-Brian

Are you aware of the situation in Colombia with Volcano Nevado del Ruiz? From your professional perspective and experience, from 0 (another day in paradise) to 10 (someone call Tommy Lee Jones asap), how likely is an eruption to happen?

Our colleagues in the Volcano Disaster Assistance Program are working with the Columbians on the Ruiz activity. They are certainly aware and up to speed on the activity there.

--Wes

I have not seen a question about Crater Lake. Is it dormant? If not, what activity do you know of?

Hi LatterGap6819. The big eruption at Crater Lake was about 7,800 years ago. After that, there were a bunch of smaller eruptions, but they ended a little more than 5,000 years ago. There have been more recent eruptions at, for example, Newberry (1,400 years ago), and Lassen (1914). --Larry

Crater Lake is the most disappointing of all the Cascade Volcanoes with respect to earthquakes...about 1 eq per year on average.

--Wes

Is Mount Tabor active? Is there any activity of magma?

In or about 1905 did Mount Tabor heat up causing people to be concerned about a possible irruption?

We haven't heard the story about 1905. Many eruptions in the Boring Volcanic Field (to which Mount Tabor belongs) are about 2 million years old; but some are much younger. Rocky Butte for example was dated as about 125,000 years old. I haven't heard a specific date for Mount Tabor. --Larry

Heading to Hawaii in July and hoping to see some active lava flow. I have seen the alerts of some larger earthquakes recently around Kilauea. Is anything happening there or just a lot of underground activity?

This is Mike. There's always a lot of underground activity at Hawaiian volcanoes! Kilauea has been taking a bit of a nap for the past few months, but at some point it will wake up. If it does by the time of your visit, there are lots of places to view the lava activity from the summit area within Hawaii Volcanoes National Park. Even if there is no eruption, the Park is amazing, and you can see lots of recent activity. It's worth it, no matter the eruption status!

I drive an 18-wheeler for food distribution regularly across the Cascades in Oregon (and as far south as Shasta). My family all worries that I'm gonna die in an eruption (or earthquake) living up here.

How likely am I to hear an "I told you so" in a theoretical surprise joining of the afterlife?

I'd say that you driving an 18-wheeler (or any vehicle of any kind) is more likely to have you pushing up daisies than any volcano or earthquake ever would. Also, walking...walking down the sidewalk of any street is probably more likely to get you killed than a volcano or earthquake. This could become a very long list.... - Wendy

This is Mike. Man...tough family if the first thing you hear in the afterlife is "I told you so!"

Volcanoes give warnings, and the Cascades are pretty well monitored (and becoming more so every year), so we're unlikely to be taken by surprise by an eruption. Earthquakes are tough, though. There can obviously be big ones in the Pacific Northwest, and those don't given warnings in the same way that volcanoes do. So preparedness is key. But the real hazard areas for earthquakes tend to be closer to the coast, and the hazards decrease with distance.

What are volcanoes of concern in the cascades today?

Many of the major volcanoes in the Cascades have had some sort of activity in the past 4,000 to 10,000 years. They all have their own unique styles of activity. Fortunately, many of them are remote and do not have large populations very close by. But several of them have a habit of shedding large volcanic mudflows that can affect communities far down valley, and some are explosive enough to send substantial amounts of ash down wind. As noted in answer to another questions, we have about 1-2 eruptions per century in the Cascades. We monitor the major volcanoes for any signs of unusual activity and will notify the public and public authorities of any changes that concern us. -- Jon

Hi zmunky. Mount St. Helens of course is #1, because it's the most frequently active and most explosive. Mount Rainier would threaten more people however, especially with lahars down the Carbon and Puyallup River valleys. Newberry Volcano could produce lava flows and cinder cones that threaten Bend. If another lava dome started growing on the south side of Mount Hood (as it did in the 1700s), Timberline Lodge and Mount Hood Meadows would be threatened, along with houses in the Sandy River Valley. --Larry

All of the Cascades that have a Very High Threat Rating are concerning enough that they are monitored continuously. But if you look at the geological record, Mount St. Helens is the most likely to erupt next. Indeed, it has the most earthquakes of any Cascade volcano (followed by Rainier and Hood). But background earthquake activity is not a reliable measure of the potential of eruption.

--Wes

How did you all find your passion in volcano research? There's so many topics to choose from in earth science and even geoscience!

Honestly, I knew that I liked volcanoes and then I just looked around for opportunities that were interesting. The opportunities were earthquake-related in my case.

--Wes

I like volcanoes because they are instant geology. I went to a school with a heavy focus on seismic creep and sediments.... *yawn* I needed excitement! - Wendy

Considering a move to Vancouver myself for a new job, anything I should know ahead of time?

There are two seasons--cold rain and warm rain. And make sure you have a passport if you mean Vancouver, British Columbia--a roughly 6 hour drive north of Vancouver, Washington.

If you move soon, you will be fooled by the best weather ever in the history of asking for good weather. Come November you'll question your choice...come January, you'll need a vacation to a sunny place. - Wendy

Hi trogdor147. Vancouver (Washington) is not within any volcanic hazard zones. Except for the slight possibility of a little ashfall if the wind is blowing in an unusual direction, you have nothing to worry about. Earthquakes are a bigger concern. --Larry

Yes. From the top of Silver Star, you can see 5 volcanoes on a clear day. - Liz

How do you feel about Bill Wurtz?

https://youtube.com/watch?v=elizAugXVcI

You gotta give it to him, he's got a lot more views than any of our USGS content...

--Wes

We're working on that... STAY TUNED! - Wendy

Wait, what are you going to do to Bill?

--Wes

I have heard there are advances in understanding seismographs yielding an increased awareness about potential earthquakes leading to an earthquake warning system. Are there improvements using the same kind of technology for volcanic eruptions?

Are there other technologies being explored which may be more useful that seismographs?

Good question! I can help clarify:
It sounds to me like you're talking about the USGS ShakeAlert Earthquake Early Warning system. This system uses the thousands of seismographs installed over Washington, Oregon, and California to detect earthquakes as they happen, computers quickly calculate the estimated areas and determine which areas will shake from this earthquake that has already begun, and sends an alert to all receivers within that area, which includes Mobile phones. So basically, once an earthquake has begun, the system lets people and things in the area know that it's going to shake soon - giving them time to protect themselves. It's only seconds, but it's better than what we had previously for earthquakes, which was zero seconds of warning. You can learn more about the system (which is really cool!) here: https://www.shakeAlert.org
So from that - when it comes to seismographs - more seismographs provide more and better information - this is true at volcanoes too! A volcano with more seismometers can detect smaller, and deeper earthquakes, so more seismometers can provide a much better picture of what's going on at the volcano, and notice when something abnormal is going on, too!

But seismometers aren't the only instruments used at volcanoes - GPS, tiltmeters, gas measurements, stream temperature and chemistry, and infrasound are just a few of them - the BEST way to tell what's going on at a volcano is a combination of all of these parameters.
-Brian

Nothing is more useful than a seismograph. NOTHING!

--Wes

Oh yeah? ...What about 12 SEISMOGRAPHS!?
(I was hoping you'd pop in in defend the all-powerful seismology - thank you!)

-Brian

👋🏻- Washingtonian born and raised here. If one of the volcanos in the state were to erupt, what would that look like for the Spokane area? (Besides school being closed for a week and higher wheat yields)

Hi omgitscarebear. It would look a lot like what happened in 1980. Since our modern society depends a lot more on electronics, there may be concern about that. Cities in eastern Washington are also now more aware of the threat of ash than they were in 1980, so hopefully there would be better commuication to warn them. Agricultural impacts would depend a lot on the crop and the time of year. In 1980, wheat wasn't much affected but the raspberry crop in Clark County was hit pretty hard.

Could (has) an eruption be strong enough to yeet material out into space?

Is Olympus Mons a former shield volcano?

Are Venus volcanoes still active?

The highest recorded volcanic plume was from the recent Hunga-Tonga eruption at 56 km, which beat out the previous record from Pinatubo (40 km). Neither of these exceed either of the suggested space thresholds (the Karman line at 100 km or a 80 km above mean sea level). -EMB

Yes, Olympus Mons is a shield volcano. Volcanoes on Venus were long thought to be dead, until a recent study that re-analyzed Magellan mission radar data from about 30 years ago and showed one of the volcanoes changing shape between two pictures, suggesting possibly a new lava flow. -EMB

Any volcanos in the USA we should worry about?

No need to worry! We (the USGS and partner agencies) have many of the potentially threatening volcanoes pretty well monitored. When the volcanoes are showing signs of increased activity, we work closely with our emergency management partners (hi WA EMD) to ensure they have all the info they need to help people remain safe in the event of an eruption. There aren't currently any volcanoes showing heightened activity in the contiguous U.S. A few volcanoes in Alaska are erupting or might erupt at any time, but they are far from populations of people. The Alaska Volcano Observatory works closely with the FAA to ensure arctic air traffic remains aware of ash clouds. - Wendy

What are your thoughts on the dangers of volcano tourism, for example visiting Hawaiian lava fields or Whakaari/White Island in New Zealand? The White Island Eruption in 2019 resulted in 22 fatalities and some pretty horrific injuries, and legal battles are ongoing. The survivors claimed the dangers were downplayed, but the tour operators argue that the appropriate disclaimers were signed and the fact that you're walking on an active volcano should have made the danger self-evident.

Do you think tours and tourism in active volcanic zones should be allowed to go ahead? How active is too active? How much liability do you think tour operators should take on?

Dear Tahituatar: I don't think it would be appropriate as a volcanologist to state an opinion about Whaakari during an active lawsuit; but as a general matter, U.S. volcanologists have become very conservative about going near active volcanoes. When the lava dome was growing at Mount St. Helens from 2004-2008, for example, no one was allowed in the crater. No volcanologists, no hikers. Nobody. It produced only a few small explosions during that four-year period; almost all of them were between October 1 and 5, 2004. --Larry

Good, and complicated question! I will answer parts of it.
I think volcano tourism is important - it's an opportunity to learn about these really fascinating features of our planet by being there, and volcanoes are such unique environments, and they're a really important part of the history, and culture of an area. That being said, there are definitely safe ways to visit them, and there are definitely less-safe ways to visit them, and really important part of volcano tourism is that people need to understand their risks when they do it.
Mt. Rainier is in normal, or background levels of activity right now for instance, which is a great time to visit it, but even now, there are risks you take by going to a high-elevation, isolated mountain with steep cliffs on all sides, and possibilities of sudden weather change and exposure that are a possibility at all mountains - in addition to rock falls and avalanches, and other hazards like this, that really could occur at any mountain. Many people understand these hazards when they visit, but just take a look at ranger accident logs to see that not everyone does, and many people fall victim to not being prepared, with bad footwear, lack of proper hydration, and other dangerous situations. Not volcanic, but an example of the importance of how knowing the hazard is always important for your safety when you go somewhere.
We really hope that the communication and information we provide now can help people understand and make informed decisions. The big thing about a volcano in a state of unrest is that magma is close to the surface. Here's it's close to the water table, and if magma touches a large enough quantity of water, the result is a violent explosion as that water flashes to steam and expands by 1000x in volume (like what tragically happened at Whakaari in NZ) - it's possible to know that there is magma close to the surface, but predicting exactly when and where the magma runs into that water is impossible. Not to mention that magma near the surface makes slopes less stable, and other hazards... Even Stromboli, one of the most well-behaved volcanoes on the planet, where people walk up and watch the bubbling lava eruptions, has had surprise pyroclastic flows - some of which have unfortunately resulted in the deaths of tourists. There is unpredictability in active volcanic areas.
So during a state of volcanic unrest, there is an area within which these hazards are most likely to occur (the Near-Volcano hazard zones on USGS Hazard Maps), and the main reason for that is the unpredictability of hazards at that time. And if people really want to go into that area during a period of unrest, I personally believe they need to understand the risks that they're taking. That within that area, extremely dangerous hazards can occur with very little to no warning at all.
...There are different levels of unrest, that provide different levels of gambling? But I think it's really important for people to understand exactly what level of risk they're taking. Volcanologists going in to monitor the volcano? I hope they understand the risks. And before a company takes people into an area of volcanic unrest, I think it's also important that the customers understand the potential risks.
Clear as mud! - Brian

What are the chances of St. Helen will erupt again in my lifetime?(I’m in my late twenties).

I live in the PDX area if that matters.

Pretty good chance. There was noticeable activity back in 2004-2008. That dome is going to just keep growing.

I'd say the chances are pretty good. St. Helens erupted in 1800, 1843-57, 1980, 2004-2008. At least four times in 223 years. --Larry

Hi, I was in Seattle when it erupted, and I especially remember the people who refused to evacuate after the warnings. Then, I especially remember that when I returned home to Boston, the sky was red with the eruption dust.

Then, I remember from high school Latin class the story of Mount Vesuvius near Pompei, where most of the population was burned or asphixiated. So, this volcano eruption scenario seems somewhat frequent, right?

There are some parallels between the two scenarios in that they were large eruptions, but there are also some big differences. For a big one, Mt. Vesuvius was not a well-monitored volcano in 79 A.D. (and while it is now, it is still considered one of the world's most dangerous volcanoes due to how close it is to major populations). So for Pompeii and Herculaneum, there really wasn't official warning that the volcano was going to erupt. For St. Helens in 1980, there were signs of an eruption for months leading up to it, so there was warning, and there was an understanding of what could happen - but the ultimate style of eruption surprised everyone.

Every eruption around the world (unfortunately, some of which end in tragedy) help scientists to better forecast what might happen at the next eruption - which helps them work together with local officials to help get more people out of harm's way. But there is still a lot of uncertainty involved, especially with exact eruption timing. This can be a huge challenge, because people look at the volcano and don't *see* it erupting, so they figure everything is fine, and get antsy about getting back to their activities (which might be their livelihood, like the loggers around St. Helens - so understandable). There are a lot of factors at play, and a lot of reasons people may choose to stay in a dangerous area. We just try to ensure that they actually understand the risk, so when they make that decision, they understand the risk they're taking for themselves.

Hope this helps -Brian

What’s your favorite food to eat near a volcano?

This is Mike. Spam musubi. There's nothing better during a hot and humid day working on a Hawaiian volcano. Or any volcano, really.

Hawaiian sweet bread! Every time I visit Hawaii, I bring my breakfast to one of the overlooks and have developed an odd sensory association with sweet bread and sulfur gas. - EMB

Smores. But only if they're cooked properly (:-). --Larry

I still have some ash from the 1980 eruption.

Is that useful for anyone for scientific research, or can that be pretty much acquired by digging these days?

I believe my family was in the Portland area when they scooped it.

Hi Artisane. If your local high-school science teacher doesn't want it, we'll take it! Please contact us using this information.

Hello, and thanks for doing this AMA.

How does the eruption of Mt. St. Helens compare to other eruptions that have taken place since humans have been around?

In the Cascades, Mount St. Helens has been the volcano with the most frequent eruptions. Parts of its 1980 eruption were on par with behavior during past eruptions (e.g., the large volcanic mudflows that were triggered, the pyroclastic flows that formed the Pumice Plain). The large landslide (called the debris avalanche) was not the first time that MSH 'fell apart'; rather it was at least the third time over the past 20,000 years. Nor was it the largest landslide in its history--the one that happened 20,000 years ago was a comparable size. The ashfall was pretty run of the mill for its past history. The one aspect that was a bit unusual and out of the ordinary was the large 'lateral blast' current that swept across the landscape to the north. Although similar processes have been documented in its geological past, they were far, far smaller in size. On a global scale, the magnitude of the 1980 eruption of MSH was nothing extraordinary. The eruption of Mount Mazama that created Crater Lake was far larger, Pinatubo in 1991 was much bigger, as was Tambora in the 1800s. The size of the 1980 eruption of MSH was of a magnitude that happens a couple times per decade globally.

You can see a comparison of eruption sizes (using volume of magma erupted here: https://www.usgs.gov/media/images/comparison-eruption-sizes-using-volume-magma-erupted

Were there any interesting geological/ecological surprises post-eruption?

I presume you're referring to the 1980 eruption? Lots. Many volumes of papers written on these topics. From a volcano perspective, we learned that big volcanoes can collapse to produce giant landslides. We also learned that lateral blasts can blow down forests. --Larry

This is Mike. One neat thing that happened after the May 18, 1980, eruption was that there were 6 years of lava dome growth that generally occurred as discrete eruptions. These events were monitored, and were accurately forecast by volcanologists -- pre-eruptive warnings were issued about the timing, location, and style of the future eruption. It remains the best example of eruption forecasting -- prediction, in fact -- and is a testament to what is possible when you have good knowledge of the volcano and lots of monitoring data.

How many Volcanoes are in the City of Portland? Or Vancouver? What are the names of them?

Hi LatterGap6819. Most of the hills in the Portland lowland are old volcanoes; Rocky Butte, Mount Tabor, Powell Butte etc. They are part of theBoring Volcanic Field, which ranges in age from a few million years to less than 100,000 years. One of them (or a new one) could erupt again, but they erupt so infrequently that they are not the main volcanoes to worry about in this area. --Larry

A few volcanic remnants in Portland and Vancouver area include Mount Tabor, Rocky Butte, Beacon Rock, and the lake at Battle Ground State Park. -- Jon

What are the drilling depths in feet around the Cascades and Yellowstone for economically viable geothermal energy?

Current active geothermal is in small areas.

This is Mike. In the Cascades it varies tremendously. There have been geothermal exploration projects at Newbery and Medicine Lake, since those volcanoes tend to me more accessible, but nothing has been produced.

At Yellowstone, you would not have to go very deep -- boiling water is at the surface in a lot of places, and elsewhere it is only a few hundred feet down. But drilling there for energy production is illegal by act of Congress. The issue is that energy production could have an impact on the hydrothermal features in the region, like the geysers and hot springs. This has happened in many other places worldwide -- geysers in New Zealand, California, Chile, Nevada, etc. have gone dead when energy production started nearby. Imagine if you went to Yellowstone and Old Faithful wasn't erupting anymore! The area has been explored, but even outside the park it's not allowed, since the subsurface water systems don't stop at the park boundaries. Energy production outside the park could still impact features in the park.

How accurate was the movie based on the event? In respect to the science. I saw it when I was little.

Most movies about volcanoes are Hollywood's attempt to grab your attention. When Dante's Peak was in production, the producers and Pierce Brosnan came to CVO to chat with volcanologists. That movie contains elements of truth in it, but certain aspects were clearly fictionalized for cinematic effect. But hey, find your favorite one, sit back with some popcorn, and enjoy a couple hours of mindless entertainment. -- Jon

What volcanoes in the Rocky Mountain and Pacific Northwest areas appear ready or overdue for eruptions? How do you know?

Hi EndPsychological890. We generally don't use the word "overdue", since eruptions are not very regular. But we do have an idea which volcanoes erupt most frequently, and use that as an indicator of which are most likely to erupt again. Mount St. Helens of course is the most active by far, with an explosive eruption about once per century. Lassen erupted in 1914. Most other volcanoes in the Cascades erupted up to a few times per millenium. There have also been eruptions in the past few thousand years at Death Valley, in the San Francisco Volcanic Field, Craters of the Moon (ID), and even at Dotsero Cone in Colorado. Which will go next? Good question. --Larry

Do you have an impact study of yellowstone caldera if it erupts?

Also curious if you have soil boring database for Yellowstone National park. I am curious about what type of soils and bedrock the park have.

This is Mike. Most eruptions of Yellowstone are not big explosions, but rather lava flows. And those really won't impact much outside of the immediate area. There might be a minor explosive onset for such lava flows, but nothing like most people imagine when they thing of Yellowstone erupting. There have been a few dozen lava flows since the last huge Yellowstone explosion.

If there were to be a major explosion, we have done models of what the ash fallout might look like -- you can read about that at https://www.usgs.gov/volcanoes/yellowstone/modeling-ash-distribution-yellowstone-supereruption-2014. But even that sort of modeling is probably overestimating things. New research suggests that these big explosions are not all-at-once events. Rather, they might be multiple events separated by up to decades. Geologically that's instantaneous, but on the scale of a human lifetime it might look like separate eruptions.

As for the bedrock and soils, check check out the geological map at https://pubs.usgs.gov/pp/pp729g/ (plate 1). The soils are generally clays or silica sinter in the hydrothermal areas. In the valleys with no trees the soils are glacial or lake sediments (Yellowstone Lake used to extend into Hayden Valley) And in the areas covered by trees the soil/bedrock are likely to be lava or ash flows. The lodgepole pines are good indicators of geology. They don't grow on the lake/glacial sediment, but are all over the lava and ask flows.

What is pele's hair?

What is a lahar?

What is a lava or volcanic bomb?

What is a pyroclastic flow?

What are the most common volcanic threats and are all volcanoes equal when it comes to what threats can and do occur?

Pele's hair is glass hairs that are spun out from volcanic vents on Kilauea. Named after the Hawaiian godess Pele. Lava bombs and volcanic bombs are clots of lava thrown from volcanic vents. Pyroclastic flows are avalanches of hot magmatic material that casccade down the flanks of volcanoes, usually when lava domes collapse. The most common volcanic threats are from volcanic ash, which can spread over a very wide area and threaten aircraft as well as people on the ground. No, not all volcanoes are equal when it comes to their threats. Kilauea volccano produces mostly lava flows that can burn howses but usually don't kill people . Explovie volcanoes, like Moiunt St. Helens, can kill people if they're in the wrong place.

I think Larry was the one who provided the excellent answer here. But so you know, we have a glossary. We're hoping to have a video glossary someday. :) - Wendy https://www.usgs.gov/glossary/volcano-hazards-program-glossary

Is this not a live video?

We're answering text questions, not doing a video. Feel free to ask questions! Thanks for joining us. -- Steven

How active is Mt. St. Helens? Example: Earthquakes, Steam, any activity

Is the magma rising in Mt. St. Helens?

Plenty active! There are commonly earthquakes occurring within the volcano and steam coming off of the 2004-2008 dome in the correct atmospheric conditions. That being said, any deformation is below our detection threshold and the gases coming out are typical of a dormant volcano. And yes, magma is recharging in the system based on earthquake and long-term deformation rates.

--Wes

Why there are not krakatoa like eruptions orrurring anymore on earth?(tectonic plates or any other reason)

Eruptions of that size occur generally every few decades to centuries. And there have been a few of that rough magnitude since 1883 -- for example, Katmai (Alaska) in 1912, and Pinatubo (Philippines) in 1991. One category bigger would be something the size of Tambora (Indonesia), in 1815. Those happen on typical timescales of 500-1000 years.

-- Mike

Are there any estimates of the probability of a major Mount Rainier eruption in our lifetimes (say the next 50 years)? How do we arrive at those probabilities? What should locals make of them?

Hey TryingToBeHere, good question,

There's typically 2 eruptions in the Cascades per Century, so the chance is certainly there. It's an active volcano, it's erupted before, and it will erupt again. Whether or not that's in our lifetimes is tough to say. however, because of the number of people at risk from its lahars, this is one of the most well-monitored volcanoes on the planet.
Because there is this chance, we highly recommend learning about what hazards you might face in your area and getting prepared for them. If you live in a lahar (volcanic mudflow) hazard zone, it's important to know how you're going to be alerted if a lahar occurs, and have a go-bag ready with the necessities, because it's unlikely your home will survive a lahar.
Even though a volcanic eruption is an unlikely event, the consequences are high. Getting prepared for this with local alerts and a go-bag will also help you to be prepared for much-more likely events, like a flood, or a home-fire, for both of which it's important to have a go-bag packed and ready, just in case you need to evacuate. Whichever hazards are in your area, being prepared for them is a wise choice. Check out mil.wa.gov/preparedness for some basic tips to get you started - then I'd recommend looking for your county's emergency management page to see if they have more specific information for your area.
Hope this helps!
-Brian

Is there anything anyone can do to force an eruption and if so could it be weaponized? Signed america

Volcanoes , like earthquakes/tsunamis fall into that too-big-to-control-probably-shouldn't-mess-with it category. There have been several attempts to channnel lava flows away from populated areas that have been entertaining, but failed. Here are a couple of links to some stories about that (and just how complicated it is on soo many different levels:
https://www.usgs.gov/observatories/hvo/news/volcano-watch-what-does-it-take-successfully-divert-a-lava-flow
https://www.usgs.gov/news/volcano-watch-did-aerial-bombing-stop-1935-mauna-loa-lava-flow

But overall with And the amount of long-term impacts the eruptions cause to people living nearby?
...Just no.
-Brian