We're volcano scientists and experts, ask us anything! Today is the 42nd anniversary of Mt. St Helens' eruption.

What does Hollywood always get wrong when depicting volcanoes?

This is Mike. I feel like movies generally want to throw every hazard at once into the pot, or make things happen too fast. Dante's Peak is a great example. Having the fluid lava flows along with the destructive ash cloud is a bit...unrealistic. So is having an entire lake suddenly turn into acid so concentrated that it burns you. But they had to get rid of Grandma somehow, so...

Follow up question: do all volcanoes hate grandmas?

Volcanoes love grandmas! Hollywood, on the other hand.... - Liz

I remember visiting the Pacific Northwest shortly after the eruption and there were tourist t-shirts made showing a guy in an OSHA-styled hazmat suit and labeled “OSHIT: Official St. Helen’s Investigation Team”. Was that pun a flash-in-the-pan? Or has it had legs in the years since?

This is Mike. Never heard that one, but I wasn't part of the 1980 response. I imagine there were lots of puns making the rounds in those days. In the 2004-2008 response, there were signs on the drive up to the mountain that said "Watch your ash up there."

What dangers does Mt Rainier pose that makes it uniquely dangerous to those like myself, living in its shadow?

If you live in the shadow of Mt. Rainier, especially in one of the river valleys, your biggest danger is lahars, or Volcanic Mudflows. While these aren't unique to Mt. Rainier, with the massive amounts of snow and ice frozen on that volcano, they are significant. These destructive flows can travel miles downstream.

Check out the Hazard Map here, to see where those lahar hazards (warm colors extending away from the volcano) intersect with where you live, work, or commute: https://www.usgs.gov/volcanoes/mount-rainier/volcanic-hazards-mount-rainier

If there are multiple intersections, make sure you have plans for how to be alerted about the danger, and where you'll go when you receive that alert for safety! Pierce County's Active Volcano Web page has some excellent resources to get you started there: https://www.piercecountywa.gov/5824/VolcanoREADY
-Brian

How much of a threat is Mt Rainier. Is it realistic for it to blow anytime in the next 100 years? I'm relatively new to Washington and living near volcanoes and it's beautiful; however, I am not really sure what kind of actual danger I am looking at daily.

And thank you so much for that hazard map!! I am very close to the yellow lahar area yikes!

This is Mike. Rainier actually is not known for major explosive eruptions. It's more of a lava producer. The ash layers around the volcano are all rather thin, so it doesn't tend to erupt in the style of St. Helens or Glacier Peak. The big hazard at Rainier is from mudflows, which can be far reaching and could even occur without an eruption. Those would impact river valleys that drain the mountain. There's more on Rainier hazards at https://www.usgs.gov/volcanoes/mount-rainier/volcanic-hazards-mount-rainier.

Thank you for doing these regularly. They are great AMAs! I work in the Port of Tacoma. How much time from the Mt Tacoma "Oh SHIT, SOMETHING IS HAPPENING!" Moment until the Lahar washes out my office?

I live in the North End of Tacoma. We're about 400 ft above sea level and and that part of Tacoma is on bedrock. I always tell everyone in a "normal" eruption, we'll be mostly fine. But the risk is if the eruption starts causing earthquakes and the Tacoma fault plunges us down. How likely is that scenario? Other than "have food and water for 7 days" what else should I have ready?

Thank you!

Hello! Good question!
While lahars have reached that area in the past, only an extremely large lahar would even reach the port of Tacoma. The larger they are, the less likely they are to occur - still good that you're aware of the hazard! Do you know how you'll receive an alert if one occurs?

As far as a volcano triggering an earthquake on a fault miles away, that's much more unlikely. The impacts of the earthquakes on the mountain will stay much closer to the mountain itself. The Tacoma fault, and other faults in the Sound area are certainly hazards that need to be considered, and they could happen at the same time as the eruption (we hope not!), but not because they're related.

As for being prepared for that earthquake, and other earthquakes, as well as power outages and other much more common hazards, we recommend that everyone gets 2 Weeks Ready in Washington ...getting as ready as you can for the big hazards will help you with the little ones, too! We'll recommend taking a look at mil.wa.gov/preparedness for some basic tips, but if you want tips more local to your area, visit Tacoma Emergency Management, and/or Pierce County Emergency Management for details.
Good questions, thanks!
-Brian

How 'early' are volcano early warning systems? Has this technology improved a lot since the good ol' Mt. St Helens' days? Also thank you for doing this ama!

This is Mike. It really depends on the volcano and the style of eruption. Small, steam-driven explosions might not have much warning because of their nature. And these can be very deadly if there are people nearby -- the 2014 Ontake (Japan) and 2019 Whakaari (New Zealand) eruptions are testaments to that. But in general, the number of fatalities related to volcanic eruptions has gone down over time, and this has been attributed to improved monitoring systems. If you've got a volcano really covered -- so you can detect small earthquakes, minor ground deformation, subtle changes in gas and thermal emissions, etc. -- it's possible to get warning that might precede an eruption by months. Good examples are Augustine and Redoubt, in Alaska, which erupted in 2006 and 2009 respectively, but that we "saw" coming for many months based on monitoring data. Some volcanoes don't give much warning, though. Prior to the 2004 eruption of Mount St. Helens, there was about a week of elevated activity prior to the first small explosion. This is why having monitoring networks and strategies in place beforehand is so critical. As we say in the business, you don't want to be playing catch-up with the volcano.

This was over a decade ago, but didn;t Italy prosecute volcanologists for bad predictions about Etna? Has that changed?

You might be thinking of the prosecution of several Italian scientists for their role in public information related to the L'Aquila earthquake in 2009. Their conviction was ultimately overturned. I'm not aware of any scientists having been prosecuted for a role in a volcanic eruption response. -- Mike

For technological changes, you have to check out some of the Cascades Volcano Observatory's "home movies" https://www.sciencebase.gov/catalog/item/5ea0b49c82cefae35a14b7f9. The films, taken by scientists after the 1980 eruption, were recently digitized and are now available online. They show scientists doing field work in the 1980-82 time period. I can't believe they were working so much inside the crater! We are doing more with remote technologies these days, to keep people safe. - Liz

Which poor souls have to respond to the comments on the USGS Volcanoes facebook page? They have the patience of a saint

We hear this a lot - and they're all represented here today, but there is one person who is the most patient of all USGS Volcanoes saints out there...

Some are better than others...actually all are great...except one.--Wes

The fact that I am Wes's supervisor means that by definition I have the patience of a saint. -- Mike

You all seem like a great team reading through these replies! <3

Well, most of us, anyway. ;)

-- Mike

What are the chances that Yellowstone will erupt in our lifetimes?

The chances are incredibly small. It's not something volcanologists are worried abut, frankly. The magma chamber beneath Yellowstone is mostly solid (maybe only 20% molten), so the system is pretty stagnant. It would take some sort of rejuvenation event (like an injetion of hotter magma) to get it to the point that it could sustain an eruption, and that sort of thing would take a while to stir the pot, so to speak -- decades to centuries at least. Maybe longer. And it would be accompanied by pretty unmistakable warnings signs -- very elevated earthquake activity, really significant ground deformation, changes in gas and thermal emissions, etc. Also, remember that the vast majority of Yellowstone eruptions are lava flows, not explosions. There have been ~20 lava flows since the last big explosion occurred 631,000 years ago. The last lava flow eruption was 70,000 years ago. That's the last time magma reached the surface at Yellowstone.

I can't really put a percentage "chance" on it, but I like to characterize it in the same way we might think about being struck by lightning. There is an average statistic that gives the odds that you will be struck by lightning. But what are the odds that you will be struck by lightning on a beautiful clear sunny day with no thunderstorms? Basically zero, right? Because the conditions don't exist for lightning. That's pretty much where we are with Yellowstone. The conditions don't really exist for an eruption right now.

​

-- Mike Poland (Scientist-in-Charge, Yellowstone Volcano Observatory)

Follow-up question: then why does Yellowstone need a volcano observatory?

Mike again -- fair question! First of all, the area is not devoid of hazards, even if a volcanic eruption is not likely. Strong earthquakes have happened before and will happen again -- for example, the 1959 M7.3 quake, which is still the largest ever recorded in the Intermountain West. Also, hydrothermal explosions (stream-driven events that do not involve magma) are a hazard. The largest-known hydrothermal explosion craters in the world are in Yellowstone. Those happen every several hundred to few thousand years on average. But small ones happen almost annually, and could ruin your whole day if you happened to be close to one when it happened. Second, what we learn at Yellowstone can be applied to similar caldera systems around the world. Yellowstone is an amazing natural laboratory, so the more we learn about Yellowstone, the more we can understand places like Campi Flegrei, or Rabaul, or Aso, or other caldera systems that are more likely to erupt (or have recently erupted) and the hazards they pose and warnings signs they give.

(Also worth noting that the Yellowstone Volcano Observatory does not just monitor Yellowstone, but also covers volcanoes in the southwestern USA -- Colorado, Utah, Arizona, and New Mexico.)

If you need an observatory to determine if you need an observatory, should you build one?

Mike here once again. That's one of the things that makes the Yellowstone Volcano Observatory sort of neat -- there was nothing to build! We're a "virtual" observatory. No building. It's a consortium of institutions (state geological surveys, nearby universities, etc.) that all work together to better understand Yellowstone. So there was no infrastructure to build! Just relationships.

You all have very specific jobs related to volcanoes. How did you decide that was what you wanted to focus on in your life? I can't imagine narrowing down to something like you have and it has really stunted me.

This is Mike. For me, specializing in volcano deformation was something I started doing after working with a professor that did similar work in college. It was really interesting, and I enjoyed doing the field work, so I found it a nice mix of office and field time. It helped that it didn't involve chemistry, since that is NOT a strong suit of mine! There ended up being a need for volcano deformation expertise when I was looking for a job, so it all worked out nicely for me.

I'm not the person that you answered, but how would you suggest someone get into the field if they are already done school? I'm about to graduate with my PhD in Geography focusing on 3D spatial modeling, and I think working with volcanos or anything that might get me some fieldwork would be awesome. Is there a need for people specialized in Geographic Information Systems/Science (GIS) for volcanology?

Mike here. Yes! GIS is very much in demand. Not only can you do amazing database-style things with GIS, but you can also use GIS to learn more about volcanic systems -- for example, calculating volumes of erupted products, studying landscapes, etc. GIS is one of those skills that can really be put to good use, especially in combination with field volcanology skills (which can be picked up in specialized classes or just through experience working with other volcanologists).

I knew that I wanted a job where I could get outside, and being a child of the 80's, Mount St. Helens was a major influence. So I got a degree in geology and geophysics and seeked out opportunities to work on volcanoes. --Wes

How much pressure are you scientists under in this field? Do you guys have fun ways to blow off side vents so you don't blow your top? Favorite mineral or rock to you?

This is Mike. Eruption responses -- like the one that many of us participated in at Kilauea in 2018 -- are pretty pressure-filled situations. But we all have our ways of recreating. I love playing ice hockey. I'm a goalie. I suck, but it's really fun. As for a favorite mineral, how can you not like Jimthompsonite? Yes, that's a real mineral. I'm not even making it up.

I agree. Mike sucks at goalie...and picking sports teams to root for. --Wes

Who would win in an all out fight to the death, Mike or Wes?

Pff. Not Wes.

-- Mike

Agree with Mike on this - eruptions that threaten and destroy people's homes are hard on everyone. I go camping, garden, and play all the zeldas (when my kid lets me have the game controls). I'm a huge fan of olivine...because it tells you that rock was really really hot before it cooled! - Wendy

I don't understand how granite mountains like the Sierra Nevada (or Mt Stuart?) are formed. I've heard people say they are the insides of old volcanoes. Does that mean there is a new Yosemite lurking under Mt Rainier and "we" just have to wait for it to erode away? Or does it also have to be uplifted by some kind of plate tectonics to become like the Sierra Nevada?

This is Mike. Neat question! Beneath active volcanoes are vast magma systems that never erupt -- in fact, mist magma that accumulates beneath a volcano stays underground and cools slowly over time. This slowly cooling magma forms granite and similar rocks. And then, over time, if they are uplifted and the overlying stuff eroded away, you get that granite at the surface. So yes, it is sort of a neat thought that one day, tens of millions of years from now, if the right conditions are in place, there might be a "new" Yosemite where Mount Rainier is today!

Are the awesome/picturesque ridges that the eastern Sierra Nevada (Mt. Whitney, Palisades Crest, Mt Humphreys, etc) is known for a product of the stuff that happens inside the volcano or erosion later on?

Mike again. Sort of a combination. The composition of the rock determines how the rock erodes -- harder rock, like granite, erodes more slowly than softer stuff, like the sediment that was closer to the surface. But where you have rapid uplift, erosion also accelerates. It's sort of a race between erosion rates and rock composition.

Which of the Cascade range is most overdue for an eruption of any kind? And secondly I remember back in the 2000s when St. Helen's was expelling small amounts of ash, is that likely to reoccur any time in the next decade or so?

This is Mike. Volcanoes aren't really ever "overdue" -- they erupt when there is a supply of eruptible magma in the subsurface, and sufficient pressure to get that magma to rise to the surface. That isn't something that happens on a schedule. In fact, many volcanoes go through "episodes" of frequent activity separated by periods of quiet. But the most active volcano in the Cascades is Mount St. Helens, by far -- it erupts about as often as all other volcanoes in the Cascades combined! It wouldn't surprise me at all if it erupted again in our lifetimes, and the most likely form of activity is like what you remember from 2004-2008 -- small ash eruptions and lava dome growth. Although you can't rule out the bigger style of event. Monitoring data in the leadup to any future eruption will be key to forecasting the style.

What’s the danger of living close to Mt. St. Helens? How close is too close?

Mike here. It really depends on the hazard. But since much of the area is a monument operated by the US Forest Service, it's hard to live that close.

Thanks for the response! How close is too close (maybe from the visitor center for example)?

Mike again. Really depends on the style of eruption. During the 20024-2008 eruption, the visitor center area was perfectly safe. But that same area was devastated in 1980. In the initial stages of an eruption, it's better to be conservative until it becomes clearer how the eruption will evolve.

What are some upcoming technologies that will enhance your understanding of what is going on with Mt. St. Helens?

This is Mike. I'm gonna take this opportunity to highlight my own favorite technology -- gravity! If the mass changes beneath a volcano -- for example, as magma intrudes into or withdraws from the subsurface -- it will result in a small change in gravity at the surface. And that's something we can measure! It doesn't work everywhere -- it depends on how close you can get to the source of mass change, and how deep that change is occurring -- but in some places it has resulted in neat insights. Kilauea, especially. There, using gravity, we were able to calculate the density of the 2008-2018 lava lake (it was about the same density as water owing to all the gases it contained), and also see subsurface magma accumulation before the onset of seismicity and deformation, probably because magma was accumulating in void space -- like cracks.

Wes and Seth will probably tell you that seismic is the best monitoring tool, but don't listen to them. They are just jealous of the extremely cool stuff I get to work on.

Pretty sure, the question was about upcoming technologies, not zombie technologies. Gravity died 30 years ago cause it was useless. It is back now, still 9.8 m/s^2, and I just haven't figured out how to kill it again.

For real upcoming technologies, check out using fiberoptic cables as seismometers. Basically by using LASERS, we can use a fiberoptic cable as a string of seismometers about 1 m apart along the length of the cable. The best part is that we can use fiberoptic cables that are already installed, or lay out our own. That is upcoming! --Wes

What kind of information to vulcanologists and seismologist share? What relationship does tectonic plate movement have on eruptions?

Lava y'alls work!

Well, we have volcano seismologists (Seth and I) in the office that track both things. Obviously at a basic level, plate movement is the reason for the volcanoes, but on a short timeline, the link between near-volcano fault movements and eruptions is...complicated. Kilauea and Mauna Loa is a place where they are very tightly linked. In the Cascades, its not nearly as simple. --Wes

What has, in your opinion, been the single most important breakthrough in vulcanology since 1980?

This is Mike. I'd have to say satellite monitoring. Since 1980, we can now "see" so much in the way of volcanic activity from space. We can detect changes in topography, thermal emissions, gas emissions, and even ground deformation. And once a volcano is erupting, we can detect ash plumes to help warn airplanes to stay out of the way. Today, satellite monitoring is part of our operational toolkit in a way that I'm not sure we could have anticipated in 1980.

In your opinion, how accurate is the lava fight between Anakin Skywalker and Obi-Wan Kenobi in Star Wars: Episode III Revenge of the Sith?

Emily J here: Although it pains me to think about Episodes 1-3, I'll take a stab at it. First, the lava looks to be basaltic (think, Hawaiian) so it would be incredibly hot (probably =>1200 C). Jedis are powerful and all, but the heat coming off the flow would have scorched them. Jumping around on bits of cooling crust forming on the lava would be...challenging, and I expect the crust would have fractured under their weight. May the force be with you!

Having the high ground is indeed better in that case - probably at least a couple hundred degrees cooler.
-Brian

What effects are anticipated in Seattle (specifically Seattle, not surrounding cities such as Tacoma) when Rainier erupts? Obviously ash fall, but anything else?

Good question! Potentially ash fall, but only if the wind is blowing in an unusual direction (possible, but unlikely).

But not all impacts of an eruption are direct. Seattle could certainly experience economic impacts, as many of the people that work there live in Pierce County, and they and their commutes could be impacted by lahars travelling down the Puyallup and White River areas.
In the past, lahars in these rivers have also led to increased sedimentation flowing into the Duwamish Watershed, which could impact the ports for years as it builds up. After the 1980 MSH eruption, parts of the Columbia River needed to be dredged because of all this excess sediment, so ships could get through. So as a major port, these are possible impacts.
An eruption is often not just a single event, but can also last months to years.
So definitely more indirect impacts (besides any ashfall, which would be a major nuisance in a populated city), but these are certainly things to consider.
-Brian

Hello, and thank you for this AMA. I have a few questions, if you don't mind.

1. Have any of you read (and/or are familiar with the reputation of) this New Yorker article that made the rounds back in 2015 titled "The Really Big One: An earthquake will destroy a sizable portion of the coastal Northwest. The question is when."? It paints a pretty stark picture, and I was curious if any of the major claims hold up. It relates to volacoes in that it attributes the inevitability of this earthquake to the North American West Coast's placement along the "Ring of Fire".
2. For Larry Mastin, I was curious to ask about how volcanic ash impacts aviation. Is that something that has an effect even if a volcano isn't visibly 'smoking'?
3. For Wendy Stovall, I was wondering how you communicate risks related to Yellowstone to prospective visitors and residents of the area. It seems like the public oftentimes has trouble assessing risk for rare events like volcanic explosions, such as for Yellowstone volcano. How do you effectively communicate with people when the sky isn't falling (and how do the ways you communicate with the public differ when it is falling)?

Hi! Wendy here - We tell people the truth whether the sky is falling or not! Yellowstone has a whole host of other possible hazards beyond any that include magma. It's certainly more likely that a person would be charged by a bison or mauled by a bear while visiting Yellowstone than be alive on the earth anywhere when Yellowstone erupts again (if it ever does).

Other ways are to suggest that people hold us accountable - there are many doomsayers out there who claim that volcanoes are going to erupt in days (or so), but they never do. We (the USGS) consistently release hazards and warnings for volcanoes that ARE showing signs of unrest (certainly in Alaska and Hawaii, and in the past at Mount St. Helens). We do this when the sky isn't and is falling - alerting people from things as small as ash that's been resuspended in the air by strong wind to lava flowing through neighborhoods.

The communication landscape changes pretty quickly on decade-long scales, however. And we have to continue to be where people are and to speak to them in the language they speak (e.g. local community meetings, to Instagram). If we continue to be out there, we hope people will continue to listen to what we have to say.

This is Brian - Very familiar with the New Yorker Article, and it comes up a lot! There are certainly some accuracies and inaccuracies within it. In short, though - This type of earthquake, followed by a tsunami would be devastating to the Western Pacific Northwest, so while some claims in that article are taken a bit out of context (i.e., "everything west of I-5 will be 'toast'") "starkness" is accurate. We're well aware that it will take months to repair some vital infrastructure like roads and bridges, which makes bringing resources into the area much more difficult.
I do also recommend reading the author of that article's follow-up, that addressed some of these misconceptions: https://www.newyorker.com/tech/annals-of-technology/how-to-stay-safe-when-the-big-one-comes (Somehow that one is a lot less well-known than the initial article, but it is really good!).
However, on the bright side, awareness of this hazard has led Washington, Oregon, and British Columbia to begin taking steps to mitigate the impacts of this future scenario, including strengthening buildings/bridges, improving building codes, creating vertical evacuation structures on the coast to allow those residents a place to evacuate from the waves, and more. In June, Emergency Response agencies across Washington and Oregon will hold an exercise to practice response to this event, and help learn where we can do more to prepare for this eventual disaster.
Since in Washington and Oregon we recognize that folks will be "on their own" for a little while after a major earthquake/tsunami (responders will be coming to help, but they are going to have a lot of other people to help as well), we've adopted the preparedness messaging that people should be 2 weeks ready for an earthquake. Having those supplies on hand to be self-sufficient will significantly help out in the event of a major earthquake - but will also help in any other situation that arises. You can learn more about the recommendations and get some tips on how to get yourself/family prepared in Washington at mil.wa.gov/preparedness - or reach out to your local emergency management agency for local-specific tips.
So yes, it would definitely be bad. But people are working on mitigating the impacts from all levels of government, all the way down to personal levels, and within their neighborhoods. Hope this helps!
-Brian

(And for the volcano part - yes, that subduction zone that will cause this earthquake and tsunami is the same reason we have volcanoes in the cascades, though that happens much further inland.) -Brian

What do you hope to be able to do in the future to investigate more about volcanoes?

This is Mike. Everything we do with respect to volcanoes is about inferring what is happening beneath the surface. We can't "see" beneath the ground directly. Sort of like the way we deal with the human body -- we "see" the inside with technologies like ultrasound, MRIs, etc. I think in the coming years we'll develop more capabilities to "see" inside volcanoes. This is already happening, with the development of small seismic nodes that can be placed around volcanoes in large numbers (more sensors = more resolution of the resulting image of the subsurface). Hopefully those trends will continue. We might also have more projects that drill into volcanoes to "see" the inside directly (sort of like arthroscopic surgery). There is a project in Iceland to drill into a magma chamber and place instruments in the hole -- a magma observatory! There will be a lot of payoffs from that sort of unique research.

If 'the floor is lava,' how should I proceed??

This is Mike. Take apart the couch, and space the cushions on the floor so that you can walk on them to get to the fridge. That should cover you. Well, at least until you need groceries...

This is Seth -- I'd counter with a "this chair is a glacier". Turns out glaciers are pretty good at fending off lava.

For me, Mt St Helens is one of the most amazing places in the continental US... It's awe inspiring to stand at Johnston Ridge Observatory and see the power of the volcano, even after all these years. I had a few questions...

1) I remember hearing once that within 100 years, Mt St Helens could rebuild/fill the crater, and 100 years after that, it could build back it's peak. What are your predictions?

2) Is Rainier the tallest cascade volcano that ever was (has it been taller in the past)? It seems that Mt Mazama was shorter (before it became Crater Lake). Were there any other Cascade volcanoes that were tall/taller before collapsing (broken top, maybe)?

Re: Mount St. Helens...Our best guess is to look at other similar volcanoes. One volcano in Russia called Bezymianny had a very similar eruption to MSH in 1956. Currently, the dome has built back above the crater rim with only small moats between the dome and the old crater walls. Thus far, MSH is on a path that is slower than Bezymianny, but that could change during the next dome building phase --Wes

The question about elevation is a good one. Shasta is another volcano with a high elevation. Many of these volcanoes have truncated lava flows that are high on the edifice and suggest that they may have been higher at some time in the past. The elevation is a tradeoff between erosion (climate) and eruption rate. During active times, it is reasonable to expect that the volcano might be higher and during quiescent times it might be lower. I don't have a definitive answer, but it is a fun thought experiment. --Wes

Where and when do you expect the next huge eription?

Honestly, we cannot say. Answering this question would put us in a really difficult situation. It's more likely that a HUGE eruption will occur somewhere internationally. Since we are all volcanologists based in the U.S., we don't have the expertise of our international colleagues at their home volcano observatories. If you do want to keep track of worldwide volcano activity, the Smithsonian Global Volcanism program produces a weekly report. https://volcano.si.edu/ - Wendy

What are your favorite books about volcanology that are accessible to non-experts?

This is Seth - I've found "Surviving Galeras" and "No Apparent Danger" to be fascinating reads. Both talk about the same 1993 eruption at Galeras volcano (Colombia) that killed a number of people including several scientists. The books have radically different viewpoints about whether or not people should have been up at the summit when the eruption happened.

"A Short History of Nearly Everything" By Bill Bryson is written in a really fun and accessible way, and has an excellent chapter focusing partially on volcanoes. Definitely a book that helped steer me toward this path! -Brian

Seth again -- there are also two recent books about the MSH 1980 eruption that are worth reading. One is by USGS scientist Richard Waite called "In the Path of Destruction: Eyewitness Chronicles of Mount St. Helens", the other is "Eruption: The Untold Story of Mount St. Helens" by Steve Olson.

Mt. Tabor is the best volcano. True or False?

This is Emily J. It is pretty cool, even if it is part of the "Boring Volcanic Field". Another cool tidbit about Tabor and the BVF: Portland is the only major US city to have a volcano/volcanoes within city limits!

How many are in the city limits? 4? Kelly Butte, Powell Butte, Rocky Butte, Mt. Tabor. Are those all cinder cones? Are there more?

Yup, those are all cinder cones! There are volcanoes within the Boring Volcanic field east into Gresham and Boring (hence the name) and north across the Columbia river into the Vancouver WA area (Battleground Lake is a "maar" volcano, where rising magma interacted with water resulting in an explosion that excavated a crater, now lake)

FALSE! I mean, it's cool, especially if you want to play basketball while counting stratigraphic layers. But no... - Wendy

This is Seth - most folks don't know that Mt. Tabor is (or was) a volcano, so good on you for knowing that. I have probably ten volcanoes that I'd consider the "best", all for different reasons (Tabor isn't on the list, FWIW). For the "cool science" factor, the Boring Volcanic Field (of which Mt. Tabor is a member) is hard to beat, since there's no really good explanation for why it exists (the subducting Juan de Fuca plate is thought to be too shallow to generate magma beneath the Portland area).

Can an earthquake cause a volcano to errupt or vice versa?

Thanks for pointing out that FAQ u/dreadwail. A very important caveat to the "yes" answer - the volcano HAS to be primed for eruption. There must be enough liquid magma that is read to erupt for an earthquake to trigger anything. Generally, earthquakes happen around volcanoes all the time, and 99.999% of the time they do not lead to eruptions. - Wendy

What are your thoughts when you see articles posted about Mount such and such may erupted sooner than predicted, but you know its total BS and the media is just trying to use fear to sell their advertisements?

This is Mike. I HATE that sort of thing! I see it all the time with respect to Yellowstone -- which has gotta be the clickbait capital of volcanology. It's not just the media. There are all kinds of YouTube channels that have turned fear of Yellowstone into a cottage industry (and clearly a profitable one, given the numbers of channels that promote such garbage). My own take is that we just have to continue to report facts and demonstrate that we are a reliable and accountable source of information. Eventually people start to see that no, Yellowstone (or "such and such" volcano) is not going to erupt, and I think the credibility of those sources goes down. But we also have the added challenge of being a government agency. That alone is not great for "trust" among some parts of the population, but I've always tried to stress that, first of all, we are accountable for what we say and do, and second of all, we aren't politicians. Or James Bond villains. We're people, just like you.

I remember a couple years ago there were explosives getting detonated around Mt. St Helens to help map the magma chamber below, what were the results? Do they tell us anything about the near future of the mountain?

This is Seth -- good memory! That was part of an National Science Foundation-funded project called "iMUSH" (imaging Magma Under St. Helens) that ran from 2013-2016 (the explosions were in 2014). Unfortunately the project didn't succeed in imaging much magma beneath St. Helens, despite one of the most dense deployment of instruments that's ever been done at a volcano. Among the things we learned: 1) St. Helens' magma system is actually pretty small (otherwise we'd have had an easier time imaging it); 2) There's a possibility that it is fed by a reservoir some distance to the east of the volcano (i.e., magma doesn't rise straight upwards from the mantle, as one commonly sees in cartoons of magma systems in Geology 101 textbooks).

Dante’s Peak or Volcano?

This is Mike. Dante's Peak. Volcano was TERRIBLE! Except the part where the grad student died while looking for lava in the subway. That was a realistic depiction of the way graduate students are used by professors.

Ok be honest - how many times do you say "Coffee! Coffee coffee coffee coffee coffee...cappuccino, java!" ???

This is Seth -- You'd be surprised.

Dante's Peak!! (But women volcanologists are cooler). - Wendy

This is Seth -- 99 out of 100 volcanologists agree; Dante's Peak, hands down.

Representing the Cascades, gotta say Dante's Peak!

Check out some of the Live tweeting we did of the accuracies and inaccuracies of this movie last week:
https://twitter.com/theterbush/status/1524554764012322816
(Or see @WaShakeOut's tweets from the same day for more!)
-Brian

If a large scale event occurred with the Cascadia subduction, what kind of effects would it have on the area's Volcanoes?

Large earthquakes, in general, are not very good at triggering eruptions....unless the volcano is already close to erupting. In that case, it may push that volcano closer to an eruption. I'm not aware of any volcanoes in the cascades that are close enough to be triggered into an eruption, but I guess we will find out in the next Cascadia event!--Wes

Good question! Several studies have looked at this relationship in after other large subduction zone earthquakes (e.g, Sumatra, Japan and Chile), and found a minor increase in volcanic activity both due to static stress changes (permanent deformation), and dynamic stresses (the shaking of seismic waves) at distances up to about 500 km away and up to a few months after the earthquake (longer term effects). But, as Wes mentions, they would likely need to be close to eruption already. -EMB

This is Seth -- we get asked that question a lot, & it's also been one that has been the subject of world-wide studies. Those studies have found no statistical correlation between large earthquakes and eruptions occurring at nearby volcanoes in a two-week window after the earthquake, although there have been some instances where that seems to have happened. What seems to be the case is that in order for a nearby large earthquake to cause a volcano to erupt, the volcano needs to already be primed for an eruption (i.e., magma is at shallow depths as evidenced by seismic unrest, degassing, and so-on). We also have two local data points that are consistent with that conclusion; 1) There are no known Cascade eruptions or landslides associated with the 1700 M 9 Cascadia earthquake; 2) The most recent non-eruptive landslide at a Cascade volcano (the 1500 A.D. Electron Mudflow off of Mount Rainier) was not associated with a large Cascadia earthquake.

A few from me:

Which of the Cascade volcanos is looking most likely to erupt next?

When Rainer/Tahoma erupts, are we likely to see a similar explosion to St Helens? I know an earthquake and landslide caused her north face to weaken and kinda blow out, is that possible again? Honestly, I'm a little worried we might see something similar and if it's the west face, how likely is that and what would that look like for the urban areas nearby?

How long should I be prepared to be a crazy survivalist if Rainier erupts if I'm in Olympia or Tacoma?

Can you guys PLEASE help Hollywood make a scientifically accurate volcano disaster movie? I don't think they understand how awesome and terrifying realistic eruptions are. Please please please and thank you?!

This is Seth -- Apologies in advance for the long answer: 1) On average there are two eruptions per century in the Cascades, with those eruptions lasting for multiple years (MSH 1980 was 6 years, MSH 2004 was 3+ years). MSH itself erupts on average once per century, with the all the other Cascade volcanoes combined erupting once per century. Lassen Peak (California) erupted during World War 1, Mount Baker had a "hydrovolcanic" explosion in 1843 that produced lahars, Mount Hood erupted between 1781 early 1790s, Glacier Peak may have erupted a few hundred years ago, and so on. If we were living 2000 years ago the answer would likely have been Mount Rainier (it was erupting about once per century back then), but its been quiet since its last eruption ~1000 years ago. Which is a long way of saying, the second-most-likely volcano to erupt is any of the other active Cascade Range volcanoes. 2) Mount Rainier has never produced an eruption the size of May 18 1980 (largest explosive eruption ~2000 years ago was about 10% the size of the May 18 ash cloud). Large landslides have happened at Rainier that have led to large lahars (which have reached into areas where lots of people live today), mostly in association with eruptions (with the exception of the ~1500 A.D. Electron Mudflow, which was caused by a landslide off the west flank that was not associated with an eruption). 3) It's good to be prepared multiple hazards - if you're prepared for an earthquake, you'll also be in good shape for other hazardous events; 4) Dante's Peak has been the only half-way decent volcano movie coming out of Hollywood and that was over twenty years ago. Maybe in another twenty years they'll come out with something decent again? here's hoping!

I can help with a few parts of this!
First, good to be aware of where lahars are likely to occur - Rainier/Tahoma did have a similar style landslide-into-lahar that St. Helens had in 1980 about 5600 years ago called the Osceola Mudflow, but even an event this large is included in the current Volcano hazard maps. So these hazard maps do take those into account, and I recommend familiarizing yourself with them for a realistic expectation of the hazards you can expect during an eruption. Also, Mt. Rainier/Tahoma is not nearly as explosive as St. Helens - Different lava compositions, so large explosive eruptions like we saw in 1980 are not as likely a hazard there.
Here's a good link to some resources on Rainier's Hazards, and getting prepared for them that is the combined work of Hazards scientists and local emergency managers: https://www.piercecountywa.gov/5824/VolcanoREADY
As far as being a "crazy survivalist" understanding and being prepared for the hazards you might experience is never something we'll call you crazy for. We recommend 2 weeks of supplies as a good start, though this is mostly aimed at the threat of a Cascadia Subduction Zone earthquake rather than a volcanic eruption. More suggestions on what to consider adding to your kits as you prepare, and how to make sure you have communications plans in place are available here: mil.wa.gov/preparedness
Hope this helps! -Brian

What is your favorite volcano that you’ve visited? What is one volcano you want to visit before you die?

Emily J here: Ooh, that is a tough question! A few of my favorites that I have worked on: Paricutin cinder cone in Mexico (the volcano that erupted in a farmer's cornfield from 1943-1952), calderas of the Taupo Okataina regions in the Taupo Volcanic Field (NZ; and Mt. Ngauruhoe, which served as Mt. Doom in the Lord of the Rings!), Mount St. Helens.
I would love to visit Italy and see Etna, Vesuvius, Vulcano, etc....

This is Seth -- It's really hard to pick a favorite, and it also feels a little odd to use the word "favorite" given that my top-ten list includes volcanoes that have killed people. I've had memorable experiences at St. Helens, Rainier, Hood, Three Sisters, Newberry, Crater Lake, Kilauea, Katmai (Alaska), Shishaldin (Alaska), Augustine (Alaska), Guagua Pichincha (Ecuador), Pacaya (Guatemala), and Arenal (Costa Rica). I'd love to visit Vesuvius and Kilimanjaro before all is said and done.

This is Mike. I like Medicine Lake, in northern California. I always feel very comfortable and at home when I'm doing field work there. Love the place. Before I check out I'd love to visit some of the volcanoes in Japan. Never been there.

They're all so unique! I spent a lot of time with Volcan de Colima in Mexico, and highly recommend a visit if you get a chance - really neat to talk to all the people who live around it and learn about their interactions with it, from farmers, to their stories of UFOs (OVNIs in Spanish) that they've seen around it!
For more local, each volcano in the Pacific northwest is spectacular, and an amazing road trip is beginning at Crater Lake and visiting all the volcanoes as you head north all the way up to Mt. Baker. Then try to pick a favorite. Good luck!
-Brian

I live in the valley that is sandwiched between Mt. Baker and Glacier Peak. Is it true that both volcanoes are woefully under-monitored and if so, are the current methods of watching for activity sufficient enough to predict an eruption in a timely manner?

This is Seth -- the USGS published a report in 2008 (Moran, S.C., Freymueller, J.T., LaHusen, R.G., McGee, K.A., Poland, M.P., Power, J.A., Schmidt, D.A., Schneider, D.J., Stephens, G., Werner, C.A., White, R.A., 2008. Instrumentation recommendations for volcano monitoring at U.S. volcanoes under the National Volcano Early Warning System. U.S. Geological Survey Scientific Investigations Report 2008-5114, 47 pp) that described monitoring levels for volcanoes with Low, Medium, High, and Very-High Threat rankings (as defined in Ewert, J.W., Guffanti, M., Murray, T.L., 2005. An assessment of volcanic threat and monitoring capabilities in the United States: Framework for a National Volcano Early Warning System, U.S. Geological Survey Open-File Report 2005-1164, p. 62.). According to that report, both Baker & Glacier Peak are under-monitored (Baker has 3 seismometers, GP has 1). We are working towards improving monitoring networks at both volcanoes.

Could climate change affect the lifecycle of a volcano and maybe create an earlier than anticipated eruption?

This is Mike. One possibility is that climate change might result in ice loss in places like Iceland. This unloads the volcano, reducing the confining stress on the subsurface, and it might make eruptions more likely than they otherwise would have been. Other impacts of climate change are probably slighter when it comes to their impacts on volcanic activity, but it's still an area of active research.

Did you all make volcanoes in your school science fairs?

This is Mike. I never did this! I feel sort of cheated... But one year I did build a solar cooker, and I used it to cook some chicken. One of the judges really liked the chicken, which is why I think I won an award that year. That judge must have been hungry after a day of looking at elementary school science projects!

I didn't have science fairs in school....and I'm the same age as Mike! What the heck? But no, I only realized that I <3 volcanoes in my late 20's! It was go-time to be a volcanologist once I figured it out. I've certainly made up for it in the number of volcanoes I've made with my son. :) - Wendy

Are there any volcanos off the coast in the PNW? If so, how active are they? Thank you

This is Mike. There is! Axial Seamount. It's quite active, with three eruptions in the past 25 years. It's actually monitored! Scientists from NOAA -- the OSU Hatfield Marine Science Center, in Newport, OR, mostly -- have monitored seismicity and deformation associated with the volcano. It inflates before eruptions and deflates during eruptions, just like volcanoes on land!

Axial Volcano is quite active and monitored by an undersea observatory! It is also deep and not a hazard to anyone or anything that breaths air --Wes

Answer the question about Yellowstone? Are things overblown? What would happen and when is this expected? Am I going to need to buy a large umbrella?

This is Mike. Yeah...things are, indeed, "overblown". First of all, the most common form of volcanic eruption in Yellowstone is a lava flow, not a massive explosion. And even those are rare -- the most recent occurred 70,000 years ago. And second, there's no indication at all that Yellowstone will erupt anytime soon (i.e., scales of a human lifetime and beyond). The magma chamber is mostly solid (we know this from seismic imaging), and there's no pressure to get what magma there is up to the surface right now. This might change one day, but it would be something detectable - this is why we monitor volcanoes! And it would take a while -- many decades to more likely centuries or longer -- to rejuvenate the system.

But that truth doesn't generate mouse clicks or views for documentaries, so the "Yellowstone is a ticking time bomb" narrative will probably always be there. Even if it is garbage. (By the way, isn't "ticking time bomb" redundant? Don't all time bombs tick sort of by definition? But I digest...). Yellowstone is the bogeyman a lot of misinformation channels, tabloids, and "documentaries" use for mouse clicks. Sort of sad, because the place is really spectacular, in every way. It doesn't need to be "sold" by making up things about the potential for it to erupt catastrophically.

Mike Poland, our Yellowstone expert, isn’t here yet but will flag this for him to answer! Quick answer: No immediate threat at hand. - Brian

How loud was the explosion? Like would it have blown your eardrums if you were close enough?

This is Seth - One of the odd things about the eruption is that many people who were close enough to see it didn't hear it, and yet folks who were far away in places like Seattle heard it very clearly. That has to do with sound waves refracting upwards into the atmosphere past a certain distance (~20 km or so) from the source, & then getting bounced back down to the earth's surface after reflecting off different layers in the atmosphere. I've not heard that anyone experienced problems with eardrums popping from MSH 1980, 'though I understand that did happen to a few folks who were near the Tonga eruption (which was a bigger explosion than MSH 1980)

I went to a creationist symposium when I was 12 (thanks, fundamentalist parents) and the speaker used photos of the layered mudflow of St Helens as "evidence" that the layered sediment seen around the world originated from Noah's flood rather than a slow geologic process. The thinking was that Pangea was sitting on a layer of water, which god forced out from the earth as well as the rains and the continent pieces "slid" apart at 50mph and slammed into one another in their current configuration, and used the sharp peaks of the Himalayas to prove it didn't happen long ago.

So my two questions are:

1. How far back did you roll your eyes at the above paragraph?

2. What was unique about the soil conditions around St Helens that caused such massive mudflow compared with other volcanoes around the world?

Emily J here:
1. That is tough. I try not to judge others' beliefs, but it is super hard to imagine linking Noah's flood (1000s of years ago, in theory?) with the 1980 eruption.
2. It wasn't so much the soil conditions, but the fact that a huge portion of the north sector of the volcano collapsed, releasing ash, rocks, snow and ice down the volcano. This huge volume of material then flowed downslope into the Toutle river (and other rivers). The videos of the mudflows from the 1980 eruption dominantly show this volcanic mudflow (or "lahar") flowing down the Toutle, which is where you can see the deposits today. This "sector collapse" of a volcano - where an oversteepened slope catastrophically collapses - is also not unique to Mount St Helens. Since that eruption, deposits resulting from sector collapse have been recognized at other volcanoes around the world (including Mt. Shasta in N. California)

This is Mike.

1) I could tell that I need a haircut. ;)

2) It wasn't the soil so much as it was the availability of water. When the volcano collapsed, it created a lot of sediment, but also included a lot of snow and ice that had been sitting on the mountain prior to the collapse. That source of water helped to feed the mudflow. The sediment remains an issue to this day.

What's the better volcano movie, Dante's Peak with Pierce Brosnan or Volcano with Tommy Lee Jones?

Dante's Peak! Check out our Live Tweet about the accuracies/myths portrayed in the movie from last week, from WaShakeOut, and https://twitter.com/theterbush/status/1524554764012322816

Emily J here: Always "Dante's Peak" (it even features Mount St. Helens!)

This is Seth - Dante's Peak by a mile. One of its few faults is its depiction of the Cascades Volcano Observatory; the movie version of CVO is way swankier than the real-life version.

Does the CVO offer tours to volcano nerds visiting the Seattle area? (Liiiike me.)

St. Helens, Hood, and Rainier are the major volcanic trifecta of the PNW. What are your favorite Cascade volcanoes that aren’t as well known? Or other geologically interesting sites, period?

Mike here. Actually, CVO is located in Vancouver, WA! Just across the rover from Portland, OR. We don't usually do tours, but hopefully will have an open house soon (the last few have been canceled due to COVID).

My favorite non-trifecta Cascade volcano is Medicine Lake, in northern CA. Cool geology, quiet, and always beautiful. As for other great geology, the story of the Missoula floods is hard to beat. All of eastern WA has a tale to tell in that respect, and some gorgeous scenery to boot!

What are some landmark advancements in technology in this field that have helped understand volcanoes better?

Also, what are the team's views on Disney's 'Lava' short? :D

Oh.....what a wonderful animation that is!! I truly lava its depiction of rejuvenated volcanism! The start shows the true growth and shrinking of a Hawaiian hot spot volcano - and the second eruption depicts how rejuvenation can happen after a volcano has been inactive for tens to hundreds of thousands of years. Diamond Head crater on the island of Oahu is a really great example of rejuvenated volcanism. https://www.usgs.gov/observatories/hvo/evolution-hawaiian-volcanoes - Wendy

Landmark advancements: the internet (data availability), cell phones (telemetry), microcomputers (all instruments). We've really benefited from general technological advancements. - Wendy

Which active volcano currently poses the biggest threat to an established population?

This is Mike. My vote would be Vesuvio (Italy). It has a history of violent eruptions and is next to Naples, which has at least a couple million people in the greater metro area. But there are also many in Indonesia and Central America that share those characteristics -- a history of large eruptions and located in densely populated areas.

A lot of talk has been made about the eruption of the Cumbre Viejo at La Palma potentially erupting at such a force that the island would landslide into the ocean. Has further research strengthened or weakened that theory?

-concerned US East coaster

This is Mike. Yeah, we dealt with this question a lot last year. And we wrote an article explaining why this was so very unlikely (https://www.usgs.gov/observatories/hvo/news/volcano-watch-canary-islands-mega-tsunami-hypothesis-and-why-it-doesnt-carry). The idea was proposed by a couple of scientists more than 20 years ago, and it got a lot of attention, including in some very dramatic documentaries. But in the years since, the idea hasn't held up to scientific scrutiny. Better tsunami models have shown that the waves would not be as large by the time they got to the east coast, more detailed study of La Palma itself shows that the collapse blocks are not near as large as the original research hypothesized and did not collapse all at once (but rather in piecemeal fashion), and no deposits from tsunami as big as those that were suggested have ever been found on the eastern seaboard of the US (despite known repeated collapses of Canary Island volcanoes). Of course, the documentary makers will never come back around to present the latest and most accurate information -- they've moved on to other things. As a result, much of the public is left with the original, flawed hypothesis.

Another example of this kind of thing is the so-called "Toba catastrophe hypothesis," which has been thoroughly debunked, but remains "common knowledge" among many because of the was it was highlighted in documentaries and by the media when it was first presented. The more detailed follow-up work sadly does not get the same amount of media attention.

Why don't we see diamonds associated with the Cascade upthrusts? What tectonic conditions lead to them?

Diamonds are formed extremely deep in the earth's mantle between 150-450 km deep, and are often mined out of a small number of the known kimberlite deposits (https://en.wikipedia.org/wiki/Kimberlite). The crust at the surface in Cascadia did not get uplifted from deep enough in the earth to include diamonds (https://pubs.usgs.gov/imap/i2781/ ). -EMB

I'm interested in the big volcanic explosion in the South Pacific: Hunga-Tonga. Are climate effects possible for an eruption that big? It was massive- maybe VEI 5?. I've seen the video of it that reached space.

Mike here. Actually, despite the size/height of the plume, the volume of gas and ash was pretty small. Might have only been a VEI3 or 4 in terms of volume. So there won't be any climate impacts -- just not enough gas and ash injected into the stratosphere. It was a weird eruption in that respect, to be sure. Lot to learn about it.

I never thought about how interesting volcanoes could be, so my question is:

What do you feel in the most interesting thing about volcanoes?

This is Mike. I think the very concept of molten rock is almost unbelievable. I mean, it's rock. But it's a liquid. And in places like Hawaii, you can see if flowing as a liquid across the ground. That always boggles my mind.

Great question! To me it's their long-term impact on the culture around them! We don't live with erupting volcanoes in quite the same way people around the world do, but if we take a look at the stories people who have lived here for thousands of years have about the mountains, giving them each names and personalities, it's clear they have a tremendous impact on the area.
While they aren't currently erupting, try to imagine for a second how different the Puget Sound area would be without Mt. Rainier/Tahoma sitting there so prominently in view?
Just one perspective. -Brian

From a science standpoint, I'm always amazed at what we can figure out about these giant systems from a few tiny little instruments on the flanks. From a recreation standpoint, the skiing is the most interesting thing about volcanoes. --Wes

How is Glacier Peak doing? I seem to remember hearing that it has very little ongoing monitoring.

There is currently a single station at Glacier Peak, which records mostly glacier earthquakes. The volcano is quiet. There are plans to install additional seismometers and GPS sensors there, pending permit approval. Hopefully in Summer 2023, but maybe later. With that improved monitoring network, we will be able to track unrest much better in the future. ---Wes

What are some of the lesser know dangers during or immediatly after an eruption? I have family living in Tonga and an issue they faced during the recent eruption was ear pain caused by changes in air pressure (this was something I've never considered or saw in movies): https://youtu.be/tfV2dJr6sok?t=98

People who live downwind of persistently erupting volcanoes have issues with asthma and other respiratory conditions. Acid rain can also be a problem. - Wendy

Did you actively work to become this or did you stumble on the career throughout your journey? Hope that makes sense

This is Mike. I was interested in volcanology from an early age -- probably because I remember following the 1980 Mount St. Helens eruption as a kid. It was just something I always found fascinating, and I was able to pursue the interest in college. A few classes was all it took to convince me that it was the career for me!

Wes, though, probably stumbled into this career, given that he stumbles into everything.

I 100% stumbled. I was working in the early dot-com industry when I spent a lot of time watching natural disaster documentaries. I thought it would be cool to be a volcanologist, like the ones interviewed on TV....so.... I became one! It took me about a decade, but I did it! - Wendy

This is Seth -- I was 13 when Mount St. Helens erupted in 1980, and it strongly influenced my career path. I was already interested in earthquakes & volcanoes, but before 1980 I'd never thought that I could study active volcanoes in the U.S. except for in Hawai'i.

How are, or have in the distant past, the Yellowstone and Cascade volcanos related?

EDIT: To clarify, do they or have they shared magma chambers? Did they/are they forming in similar ways? Will the Yellowstone caldera be at the top of a steep mountain someday?

This is a common misconception -- Yellowstone and the Cascades aren't related and never have been, and they don't share any sort of magma system. Yellowstone formed by a hotspot -- a stationary area of melting in the Earth's mantle. The crustal plates at the Earth's surface move over the hotspot, and that gives you a chain of volcanoes that get older the farther you get from the current hotspot. Hawaii is the classic example. At Yellowstone, the older, now extinct volcanoes trend across the Snake River Plain of southern Idaho. In contrast, the Cascades formed at a plate boundary, where two of the crustal plates come together (this is the type of setting where most earthquakes and volcanoes on earth occur).

Being a different sort of volcano, Yellowstone never has, and never will, have a steep edifice, like Mount St. Helens. It is more of a volcanic field, with lots of activity spread over a broad area. It's quite different than the pointy mountains that we see in the Cascades.

-- Mike

What volcano do you feel is the most dangerous to humans?

This is Mike. Anyplace you have a volcano with a history of violent eruptions and that is located in a densely populated area, that's a bad combo. Vesuvio, in Italy, is one that has always been on my mind in that respect. But there are a bunch in Indonesia and Central America as well -- both places are very densely populated and have many volcanoes, several of which have experienced very destructive eruptions.

How many volcanologists get injured every year? Are there any statistics on injuries or fatalities in the volcanology community?

VERY few. Within the USGS, a handful to zero are injured each year, and most of those are due to sprains or general injuries that occur when hiking.

The hours of safety training and required personal protective equipment keep things really safe! - Wendy

This is Mike. Relatively few volcanologists/scientists have been killed in eruptions. According to a database of volcano-related fatalities (https://appliedvolc.biomedcentral.com/articles/10.1186/s13617-017-0067-4), the last volcanologist fatalities were in 2006 (see the table at https://appliedvolc.biomedcentral.com/articles/10.1186/s13617-017-0067-4/tables/7). Injuries are harder to quantify, but in the USGS, we're pretty careful. We have comprehensive safety programs covering everything form helicopter operations to the proper ways to wear a respirator (if working in an area where volcanic gas might be a hazard).

How accurate was Bill Wurtz's song about the Mount St Helen's gift shop?

This is Seth -- not sure which gift shop the song is referencing, but I can attest that gift shops at two visitors centers (Johnston Ridge Observatory & the Mt. St. Helens Visitors Center at Seaquest Park) are excellent.

When monitoring cascade volcanoes, how do you determine whether a seismic signal is caused by the movement of magma rather than caused by tectonic, glacial, or hydrothermal sources?

There are a couple of things we look for. The first is the frequency content. Earthquakes associated with magma have lower frequencies than regular earthquakes. The other is location. If it is very shallow and the volcano isn't erupting, then its probably due to glacial or hydrothermal sources. --Wes

I recently wrote my BSc physics dissertation on the effect of magma composition on volcanic eruption style.

One question I struggled to answer confidently was why Plinian/Ultra-Plinian/Sub-Plinian eruptions are so much more violent depending on the evolution level of the magma. I found transient eruptions easier to explain but continuous less so. Obviously viscosity and gas content are major contributors, as well as an inability to degas in more evolved magmas and a higher gas content overall. But I still really struggled to write a cohesive explanation on why they’re more explosive.

Why are Plinean eruptions more explosive than their Hawaiian counterparts?

There are often more crystals in silicic magmas (e.g. rhyolite, dacite) than in mafic (e.g. andesite, basalt) ones. Crystals don't glide past each other very well, and they block gases from escaping. So, they pressurize more intensely prior to eruption and then break apart more forcefully as they erupt. When silicic magmas have very few crystals, they form lava flows (e.g. obsidian). - Wendy

Does lava have a smell?

If so, do lava from different volcanoes smell different?

If so, why?

Oh yes....it does. It has the sweet smell of sulfur. Why....because sulfur-derived gases are prolific at volcanoes. Sulfur dioxide (which you can feel in your throat more than smell) is one of the last gases to escape from magma as it rises through the crust - it is released basically at the surface. Hydrogen sulfide (more like a rotten egg smell) forms when sulfur gases interact with water (groundwater) and can be smelled at places like hot springs or steam vents at volcanoes. - Wendy

Strong sulfur (rotton eggy) smells and burning plant material are the strongest in my memories. The sulfur smells are definitely variable and depend on how much of that gas is dissolved in the magma. The burnt smells depend on whether the lava is flowing over vegetation. -EMB

This is Seth -- I'm a seismologist so mostly try to stay away from lava (because it melts our instruments), but the times I've been close to it I mainly remember the heat rather than the smell. Although there was one time when I accidentally got a good dose of SO2 and had a hard time smelling much of anything for the next several days.

My Geology teacher in college showed us the famous video of the scientists who were the first to stand on a newly created island and then were stranded for a couple of hours. When asked why anyone would go there he replied "They are volcanologists and they are from the crazy side of the family."

Is that true and do you guys rush into dangerous situations for the science?

This is Seth -- My experience with the USGS is that we take safety extraordinarily seriously; none of us want to die doing what we do, & we also recognize that if something happens to us, that also puts others at risk who have to come rescue us. These days we perform risk-benefit analyses before we do anything that is truly risky.

Which is your favourite volcano?

Emily J here: so many!! In the U.S.: Mount St. Helens, Kilauea, Mauna Loa, Mt. Rainier, cinder cones of Oregon, Arizona, New Mexico... Outside of the US: Paricutin, Colima (Mexico), calderas of the Taupo Volcanic Zone

Mount Shasta (I love working with the lemurians) --Wes

Can similar events that created the large igneous provinces like the deccan and siberian traps occur again?

This is Mike. Yes, but these are among the rarest events in the geologic record, occurring once every tens of millions of years (the most recent was the Columbia River Basalt, right here in the Pacific Northwest, mostly 15-16 million years ago). And they don't occur all at once -- they occur over hundreds of thousands of years. It's an open questions as to whether or not we could even recognize such an event to be a flood basalt as it was happening, since they far exceed the timescales of human life.

What's the current situation with Mt. Shasta?

A few years ago there was a bit of a ruckus claiming that a Shasta eruption could wipe out most of the US West coast IIRC.

Any rumblings from that beauty?

Mt. Shasta is a "Very High Threat" volcano, and has had a history of collapses of earlier edifices. Currently, Mt. Shasta's monitoring network indicates relatively quiet earthquake activity and negligible deformation. https://www.usgs.gov/volcanoes/mount-shasta - EMB

Last summer there were around 2 dozen debris flows that came off of the flanks of Shasta, but they only impacted Highway 97 to the north and a few forest service roads around the east and south. Given the lack of snow again this year, it wouldn't be surprising to see more this summer. --Wes

I’ve spent time in the Sandy glacier caves on Mt. Hood and some of the water flowing from underground is incredibly warm, which forms the caves. My question: is there a limit to how warm this water can get? Is this considered a normal function of a cascade volcano, geothermally speaking?

I’ve spent time in the Sandy glacier caves on Mt. Hood and some of the water flowing from underground is incredibly warm, which forms the caves. My question: is there a limit to how warm this water can get? Is this considered a normal function of a cascade volcano, geothermally speaking?

Well, the water certainly can't get above boiling temperature! Most volcanoes, especially wet ones covered in glaciers, have hydrothermal systems that circulate through their structure. Glaciers/snow melts, flows downward through the porous system in the ground and is heated by the magma storage region within the volcano, which causes the water to rise again...very typical. This is also why glacier-clad volcanoes are made up of hydrothermally altered rocks that crumble really easily - this makes them more susceptible to landslides and therefore lahars. - wendy

How do you pronounce Eyjafjallajökull?

This is Seth -- Some volcanologists have taken to referring to it as the "E volcano"

With difficulty. -- Mike

https://upload.wikimedia.org/wikipedia/commons/7/75/Is-Eyjafjallaj%C3%B6kull\_%283%29.oga

I recently read Volcano Cowboys: The Rocky Evolution of a Dangerous Science by Dick Thompson and have mad respect for all you do. Has vulcanology evolved with technology so that collecting data is less dangerous or do you and your fellow scientists still need to be where the action is?

This is Seth -- Yes, technology has evolved a TON since that book was written. Webcams have reduced the need for in-person observations, miniaturization of low-power sensors has made it much easier to deploy monitoring equipment without putting ground crews in harms way, and there's a lot more that can be done by satellite now. There will always be a need for people to work close to the volcano, but the need is less and volcanologists in general have grown more aware of the need to not take unnecessary risks while working on active volcanoes.

Many of the anecdotes portrayed in that book are depicted as "cowboyesque" (hence the name). I'd say we have a LOT of safety protocols in place. Generally, we understand volcanic behavior relatively well so any risk that is taken is really well informed. Times have certainly changed in the past 40 years. Heck, the internet exists and we are able to put sensors in volcanoes then have the data sent to us hundreds of miles away - that technology has certainly decreased our need to be where the "action" is. - Wendy

Technology has certainly allowed us to deploy more remote instrumentation which keeps people from having to get into the really dangerous areas. In particular, GPS instruments and seismometers have gotten more sensitive, there are new remote ways of detecting gas, and satellite technology has gotten much better. As long as we get the instruments in ahead of time, then we can reduce our exposure. --Wes

How might lahars affect species that live in and near rivers? Are there ways we can improve these outcomes?

Unfortunately, lahars aren't really very forgiving. We can't stop them when they start, we can just get out of the way. - Wendy

To add to "how" they might be affected, I would say "long-term." Dumping a bunch of extra sediment in a river can completely change the way it flows. - Brian

Will Mt Teide on Tenerife still erupt soon considering La Palma erupted a few months ago?

This is Mike. I'm not aware of any monitoring data that indicates Tenerife will erupt anytime soon. Volcanoes don't generally influence one another in that way -- just because one erupts does not mean the adjoining one will erupt. The magmatic systems are independent and do their own things. Spanish volcanologists monitor both volcanoes, though. They have a good eye on things.

Thanks for the answer. Perhaps soon wasn’t a good word. Apparently Teide erupts approx every 100 years. It’s been 113 years since the last one.

Mike again. I would always be cautious of any source that says that a volcano erupts "every XXX years." Volcanoes don't really work that way. That might be an average, but if you look at the eruptive history of Tenerife (https://volcano.si.edu/volcano.cfm?vn=383030) you can see that the activity is by no means evenly spaced in time.

We hear this with Yellowstone all the time. "Yellowstone erupts every 600,000 years, and it has been 631,000 years since the last eruption, so it's overdue." Nope. not the way Yellowstone, or any other volcano, actually works.

My dad says in early summer of 1980, just after the eruption, our family visited Harrison Hot Springs in southern British Columbia. He says, during check in, he was advised that the eruption had caused the temperature in the hot springs to temporarily dip. We rented a room anyways and I remember we had the pool mostly to ourselves. I recently visited the area and was told the story likely was not true, but no one knew for sure. Does anyone know if it is possible?

It is unlikely (like really, really unlikely) that a hot spring in british columbia would be impacted by a MSH eruption. Gotta be in the immediate area.--Wes

What exactly is the difference between a super eruption and a hyper eruption?

This is Mike. This is EXACTLY why I hate the "super eruption" and "supervolcano" terms. If you want to read a rant on that, check out https://www.usgs.gov/news/personal-commentary-why-i-dislike-term-supervolcano-and-what-we-should-be-saying-instead). I suspect people think if there can be a "supervolcano" that there must be a "hypervolcano," etc. Nope. Totally made up. I heard someone once ask about a "mega-colossal volcano." Um, what? It's starts to sound like varieties of shrimp. Jumbo shrimp, colossal shrimp...THEY"RE JUST SHRIMP!!!!!

Sorry...you touched a nerve...

This is Emily J. Super eruptions are those that are VEI (volcano explosivity index) of 8 and by the amount (volume) of magma erupted, >1000 km3. https://www.usgs.gov/volcanoes/yellowstone/questions-about-supervolcanoes

Never heard of a "hyper" volcano...volcano that had too much coffee?

What kinds of impacts to the health of the Sound and local rivers will we see after a medium-to-large eruption? I'm thinking of how the Puyallup drains into Commencement Bay, picturing a lahar gunking up the ecosystem, wondering what fish, shellfish, eelgrass, anemones, etc. will still be viable if all that (acidic? alkaline?) volcanic matter gets flushed into an already hurting Puget Sound. 😥🌲♥️🗻🐟

Good question, and there will certainly be long-term impacts, but it's difficult to say exactly what they will be until the eruption happens. One thing to consider is that a lahar beings a huge amount of sediment with it, that will continue being added to the ecosystem for years after the eruption - post 1980 the Army Corps of Engineers actually had to build a special Sediment Retention Structure to limit the amount of sediment dropping into the Columbia River, as there was so much the river needed to be dredged multiple times to allow ships to move through.
Additionally, a very large lahar moving through these areas could potentially bring some hazardous materials with it, from homes and other elements of the built environment, and add these into the Sound. So those could have additional impacts that are difficult to quantify.
(Will see if one of the others can speak to the chemistry part, too)
-Brian

Question for the group: what do you love most about your career? The movies always make it seem like volcanologists are traveling all over the world dodging bureaucracy, narrowly missing turning into a human piece of toast, and saving lives; but I’ve always been curious about what the various jobs and specialty’s within volcanology entail.

I’ve been obsessed with volcanos since I was a kid but I had a teacher say most of the science around it is pretty “math and chemistry based in a lab or office, so if you don’t get your grades up it’ll never be an option” lol.

I love solving the "puzzle" of what is going on underground. While the particular topics that I study are pretty math intensive, not everything that we do is. Our observatory colleagues have backgrounds in a lot of different areas including communication, computer programming, electronics, safety, illustration, etc., lots of opportunities to work with volcanoes! -EMB

I wish I was better at dodging bureaucracy...--Wes

As his supervisor, I wish Wes was not as good at dodging bureaucracy. -- Mike

As my supervisor, I feel compelled to tell you that the TPS report is going to be late. --Wes

What I like about my job is being able to ask a scientific questions and then figuring out how to answer them. Or being presented with volcanic unrest (lots of earthquakes) and trying to figure out what is going on.

The fun part about being at an observatory is that we have people with all kinds of backgrounds, science, computers, engineers, etc. I know for a fact that they didn't all get good grades ;) --Wes

Emily J here: Don't let your teacher dissuade you! Yes, I use math, chemistry, and some physics, but I also spent the last 10 days in the field sampling lavas from the San Francisco Volcanic Field in Flagstaff, AZ.
There are many sub-specialties within geology and even within volcanology, so there is something for everyone!

What's the most likely next Cascades volcano to erupt? My money is on South Sister.

This is Mike. The answer to this question is always -- ALWAYS! -- Mount St. Helens. It erupts as often as all other volcanoes in the Cascade Range combined! So that's where I'll put my money.

Mount St. Helens!

Is anyone on the team moonlighting as a famous teen pop star?

Lorde, Lorde Lorde Lorde... I am Lorde...

-- Mike

Are there any studies on the effects on the human respiratory system from inhaling the ash? Spent a few hours playing in the ash and wondered how bad that really was?

Good question: Unfortunately there aren't any long-term studies available on the long-term effects of inhaling volcanic ash, but since this eruption was 42 years ago, and chroinic issues haven't been traced back to it, including from the folks working to clear the lumber from the very ashy areas around St. Helens following the eruption, the current consensus is no.
If you're interested in research on the health impacts of volcanic ash, I recommend the International Volcanic Health Hazards Network as a resource: https://www.ivhhn.org/home
-Brian

Have any movies been close when it comes to what you actually do for work?

Yeah, for sure. Office Space. - wendy

(I kid, I kid...but office work is dominant)

cliffhanger --Wes