IamA Pacific Northwest Earthquake experts. Ask us Anything. AMA!

Based on last year's New Yorker piece on the "Really Big One" i.e. the Cascadian subduction fault's potential to create a 9.0+ quake & tsunami that would completely devastate the region, how accurate would you say the tone of this article is? Are we looking at a highly probable apocalyptic-magnitude event? And lastly, is there something non-seismologists should be doing in the next few years, such as advocating for certain policies to be passed?

Maximilian: This article helped bring attention to this very devastating event. It did however over-sensationalize it a bit and overlooked all the hard work that agencies, organizations, businesses and individuals do every day to get prepared, mitigate risk and be ready to respond. There is a lot of discussion in the scientific community about the probability of a M9 Cascadia Subduction Zone earthquake in the next 50 years. Depending on who you talk to, this ranges from 10 to 14% or even higher probability within 50 years. There are a lot of important efforts and policies you could support. An example is conducting seismic safety assessments for WA State Schools. Another is supporting the building of tsunami vertical evacuation structures in or near WA coastal communities.

An M9 would have widespread effects. It could be catastrophic to low-lying areas on the coast, it could thoroughly disrupt transportation, incapacitate many businesses both through damage and disconnected supplies and ways to deliver products.

However, outside of the tsunami zone and bad buildings along the coast, the damage might be fairly spotty, with most newer structures doing ok.

John

Emory: As far policy goes, in California, many cities are adopting ordinances for mandatory seismic retrofits for vulnerable buildings such as soft-story buildings, unreinforced masonry buildings, concrete frame buildings, schools and hospitals. Policies like this will improve the resiliency of our communities and allow impacted cities to recover more quickly.

Tim and Dave--A magnitude 9 event would definitely be serious; the New Yorker article's tone was somewhat exaggerated. Tsunamis travel overland several miles from the shore, up to as much as 6 miles at the Sendai Plains in the 2011 Tohoku earthquake. Go to http://www.dnr.wa.gov/geologyportal and go into the seismic hazards catalogue where you can see estimates of the amount of earthquake damage from a Cascadia earthquake.

I live at the top of a hill in Wallingford. When the big tsunami comes, I'll be the king of my own island, right?

Tim and Dave--highly unlikely that any tsunami will reach that high in Seattle. We have modeled the inundation limit there. Go to http://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/tsunamis and search for the Seattle tsunami inundation map

But I already picked out a name for my island. Oh well. I guess the peace of mind is more important.

Gala: Hi MisterWonka. I live in Wallingford too and have my "Gala Gala" island flag ready to go in my prep kit. Maybe we could use Map Your Neighborhood to work together with other local residents (http://mil.wa.gov/emergency-management-division/preparedness/map-your-neighborhood)

Manuel Lugo: at DNR Tsunami hazards/risk page you can find information on preparedness, evacuation routes/warning signs, historic tsunamis and how they are generated.

http://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/tsunamis

On this site you can use the mapping tool to locate your home address or any other location of interest

Why did Seattle build it's brand new Emergency Management center directly ON TOP of the fault line in down town Seattle. Isn't it in the worst possible location? https://www.google.com/search?q=seattle+emergency+management&npsic=0&rflfq=1&rlha=0&rllag=47608541,-122336323,1029&tbm=lcl&ved=0ahUKEwiq8q2akerPAhVi0FQKHUm0D6IQtgMINg&tbs=lf:1,lf_ui:2,lf_pqs:EAE

Maximilian: Good question. I would contact Seattle Emergency Management and ask them.

What is the best way to figure out a route out of a city like Seattle by foot, should you be lucky enough to make it through the initial shocks?

Maximilian: Check this Seattle Hazard Map site: http://seattlecitygis.maps.arcgis.com/apps/MapSeries/index.html?appid=0489a95dad4e42148dbef571076f9b5b for more information on what the hazards are for your home, work etc. and your transportation routes. You can also contact your local emergency management agency and ask them for assistance in figuring out potential routes: http://www.seattle.gov/emergency-management.

Can we get this for other counties in the state? (You did say PNW...)

Sure. Here are some statewide maps. http://www.dnr.wa.gov/geologyportal -- Steven

Any cities that make you shake your head when you see how and where they were built?

Emory: Venice in Italy makes me shake my head!

Maximilian: Yes, too many to count!

I can't remember where I read it, but because the PNW is a subduction zone, the last time there was a big quake 300 years ago there were some spots (like Whidbey) that raised/lowered 30 feet, and Willapa Bay changed a significant depth. Similar things happened up in Alaska during their Good Friday quake.

My question is, are there any estimations on which areas around Puget Sound might raise/lower and have a higher risk of permanent flooding after the quake?

Tim and Dave--The amount of subsidence during the last Cascadia event was somewhere between about 2 and 5 feet near the coast. Uplift was mostly offshore. There were no known areas of uplift or subsidence in Puget Sound from that event. There was about 20 feet of uplift on Bainbridge Island caused by a Seattle fault earthquake about 1,000 years ago.

The Puget Sound is pretty far from the uplift and down drop due to the ground shift - those effects are much bigger on the coast.

John

How effective will bicycles be after the "Big One"? Should we be doing more to consider them as a viable option for first responders and disaster relief? It seems like electric assist cargo bikes would be invaluable in a city like Seattle when debris chokes the streets and the damage to infrastructure like bridges and overpasses isn't known well enough to determine whether or not it's safe for emergency vehicles to use them.

Bikes are my plan. I just need to ride 2 miles to get to the Seismo Lab from my house, and that's how I commute every day. Already, most days I can see the rush-hour cars backed up while the Burke-Gilman is moving fine.

John

Maximilian: I too plan on using my bicycle to get to work IF the roads are impassable when the next earthquake hits. I prefer a lighter bicycle that I can pick up and carry over debris, with a rack on it so I can bring my go bag/preparedness materials with me.

Gala: Hi PipedreamSEA! In fact there are cities that are practicing just that! Seattle Disaster Relief Trials (www.Seattledrt.org) just held an event on September 25th. As you pointed out, cargo bikes can traverse roads that would be impassable by cars.

Oooh, another one - okay, I know this isn't strictly a earthquake question, but in the neighborhood: What of the odds of seeing something cool* happen at Mount St Helens again, or was May 18th pretty much the grand finale`?

. * Cool in a pyrotechnics sort of way, not necessarily a scientific sort of way, of which I imagine we're getting a constant stream of knowledge from, and that's always cool.

Mount St Helens remains very active. It not only erupted in the 1980s, but also had more minor activity 2004 to 2008. It could have minor eruptions any time. For big eruptions, we expect (although do not guarantee) to first see a pick up in the local earthquakes and deformation.

John

Hi RetiredType40: May 18th was by no means the Grand Finale of Mount Saint Helens. Historically, Mt. St. Helens is the most active of the Cascade Volcanoes. It was active again (with some good pyrotechnics) between 2004-2008 with a number of eruptions expelling ash up to 10,000 feet. It is also the most highly monitored of the Cascades Volcanoes, and experiences many small Earthquakes every day. (so yes, certainly a constant stream of knowledge!). So considering it's activity, there is definitely a likelihood of more pyrotechnics. Agreed with you that the volcanic pyrotechnics are impressive and fascinating to watch; just remember that they can cause some serious damage to the communities around and downwind from them! -Brian

With the current infrastructure of Seattle what percent of the buildings would fall or be irreversibly damaged in the worse case scenario quake?

Manuel Lugo: At this link https://fortress.wa.gov/dnr/protectiongis/seismicscenarios/

You can find different scenarios and possible damages.

Anywhere (city, type of building) that you would never live as a result of what you know about volcanoes and earthquakes?

Emory: The type of buildings that are most vulnerable during an earthquake are: unreinforced masonry (red brick) buildings that have not been retrofitted, weak or soft-story wood frame multi-story structures that have not been retrofitted and older concrete frame buildings. Simpson Strong-Tie has some good basic information for home retrofits in our Seismic Retrofit Guide which you can find at www.safestronghome.com

Gala: Personally, I love the ocean. Living there requires considering the Cascadia Subduction Zone and its ability to produce large magnitude earthquakes and tsunami. I would live in areas along the coast that allowed for safe evacuation and shelter. I recommend being aware of your earthquake and tsunami risks anywhere you live. You can find resources to help you figure that out here:

DNR link to geologic hazards maps: non-interactive forms of the above. http://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/geologic-hazard-maps

DNR Tsunami hazards/risk page: information on preparedness, evacuation routes/warning signs, historic tsunamis and how they are generated. http://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/tsunamis

As Emory said, I'd sleep poorly in a URM building.

John

We did the Great ShakeOut drill at work this morning (California). Do you have any high potential numbers for quakes in California? If so, when? I am pretty surprised that somewhere up this Pacific Rim we both sit on, none of our three states (Cali, Oregon, WS) have been hit hard by a quake in recent times. Others on the Pacific Rim, like Japan and several South American countries have been hit hard. How have we avoided this so well? What does this mean in terms of the buckling of the rim for us?

The lack of big quakes in recent years does not mean we are any safer or in any more danger. Damaging quakes come every decade or so, with little pattern.

The last bad quake up here was Nisqually in 2001, an M6.8 deep quake under the Puget Sound, the last moderately bad one in California was in Napa, an M6.0 in 2014.

Here's a list of big quakes in California - https://en.wikipedia.org/wiki/List_of_earthquakes_in_California.

This map shows the moderate and big quakes in the Pcific Northwest since 1969: https://www.pnsn.org/earthquakes/notable.

John, the state seismologist

How close is close, when it comes to a fault line? If you built a mile from one, is it much different than being right next to it?

Emory: The level of shaking is dependent on the intensity of the earthquake and proximity to the epicenter. The further you are from the epicenter, the level of shaking reduces. However, the epicenter can happen any where along the fault line.

Probably too late to this party, but a girl can hope for an answer anyway:

I understand that earthquakes can cause massive damage and kill hundreds of people within the first ten seconds of shaking. It seems like, for an M9.0, there would be little point in being "prepared"? I mean, you'd probably be dead before you could even think about getting somewhere safe. Is this just sensationalism?

Yes, sensationalism or Hollywood. Maybe a few thousand would be killed out of the many millions of people in the Pacific Northwest in an M9 quake. Very serious indeed, but we are not talking about no survivors.

John

What's the risk Vancouver Island splits in two? I understand it is well overdue? How do we know that specifically?

Tim and Dave--the subduction zone is offshore and beneath Vancouver Island, not through it. No reason for it to split in two

Rad.

http://news.nationalpost.com/news/canada/vancouver-island-will-rip-open-like-a-zipper-when-overdue-megathrust-earthquake-strikes-experts-say

That headline is wrong to very misguided. There is a secondary fault through Vancouver Island capable of an M6 or 7 quake, but by no stretch of the imagination would it rip the island in two.

How long will it take for everything to recover once the "Big One" hits?

Or would it ever recover at all? If I were to survive the initial disaster, should I stay and hope for the best or just leave everything and move to the Mid-West/East coast or even out of country?

This is a difficult question to answer, and it is highly dependent on where you are. Certain areas will be hit harder than others by any Earthquake, and recovery times vary based on how much they are damaged, and other factors like how quickly they can be reached by organizations attempting to assist them... this could also take a long time in some areas compared to others, simply based on infrastructure damage: areas that recovery crews are struggling to reach will recover more slowly. I would suggest looking into stories from the Tohoku 2011, Earthquake in Japan for an example of how recovery works from large subduction zone earthquakes with tsunamis. Some areas recover relatively quickly, but there are still some cities along the coast (Kobe, for one) that are not recovered from this event that happened 5 years ago. That being said, on an individual, family, and community level, getting prepared now can significantly speed up recovery. Taking steps now to mitigate loss of life and damage to property can make sure that resources you need to start recovering are there. This is part of ShakeOut's suggestion to "Do One more Thing" (or more) in addition to just practicing the drill. Some suggestions can be found in the "Prepare" section of Earthquake Country Alliance's tips: http://www.earthquakecountry.org/prepare/ -Brian

They always say everything west of i5 will be screwed. What does that mean for someone in Portland like me that's right on i5? I feel like we may still be SOL considering the Columbia is obviously connected to the ocean

The "west of I-5 is toast" meme was shorthand for a specific scenario to test response for FEMA in the "Cascadia Rising" regional exercise. I-5 may well take a beating, but being just west or just east of I-5 is not a critical distinction.

For Portland, I would check DOGAMI or Oregon OES or CREW websites for details of what to expect - probably not as dire as you may be imagining.

John

Here's the link to Oregon's tsunami maps: http://www.oregongeology.org/tsuclearinghouse/default.htm

Are there ancient/old warning markers like the famous stones in Japan that marked tsunami-safe zones in other countries?

You might dig this video the Hoh Nation did with us about the Thunderbird and the whale, an old story about tsunamis. https://www.youtube.com/watch?v=J_sp_oYH0Zc&list=PLaYp9JZofBz26XydBvDbhgYmeedbS_Za4&index=4 -- Steven

Tim and Dave--Those mark historic runup from previous tsunamis. The Cascadia tsunamis in the Northwest are prehistoric so we don't know where to mark them.

We recently moved to the Port Angeles area and I wake up every morning around 4AM and panic about earthquakes. There's a lot of talk of the Seattle area and what will happen... How are the fault lines around PA? Sequim? How would a tsunami effect us over here? AM I GOING TO DIE??

I can't think of a circumstance in which possible quakes are your biggest threat, so try to keep things in perspective. If you're 10 meters or so uphill from the ocean, and in a modern structure, the direct danger of an earthquake is minimal.

Sounds as though, given your worries, you're just not going to be comfortable sleeping at the waterside.

John

Manuel Lugo: go to this link https://fortress.wa.gov/dnr/protectiongis/geology/?Theme=natural_hazards

At this link you can find a mapping tool that will help you answer some of those questions, the key is preparedness making sure you know your evacuation routes and having a survival pack for you and your family.

Tim and Dave--Go to http://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/geologic-hazard-maps#tsunami-evacuation and look at the tsunami evacuation maps.

Maximilian: A great way to reduce your anxiety is to know your risks, know your options and get prepared!

Well this says "Ask us anything" so what exactly are your plans to get an NBA team back in Seattle? In all seriousness though, what are the chances of bridges and overpasses failing? Have they been fixed or "upgraded" to withstand a large quake?

Our plan is to cheer for the Huskies.

John

Hi Maguirrem2010, Unfortunately we were not able to contact a representative from Washington DOT to be a part of this, but here is a link to some information on the Department of Transportation's plan for retrofitting bridges. This is a plan which will take time, but definitely help make the bridges more structurally sound than they currently are - Brian http://www.wsdot.wa.gov/Bridge/Reporting/SeismicRetrofitProgram.htm

When do you guys predict that the "Big One" will occur?

Tim and Dave--sometime in the future; exact time unknown but probably sometime in the next 500 years or it could be this week

So what you're saying is I need to panic?

The big one, an M9 along the coast, is estimated to have roughly a 10 to 20% chance per decade of striking. It's a roughly once in 400 to 500 year event, and we're in the window in which it could hit.

John the seismoguy

/u/TornadoApe Time to panic.

Be Prepared. Not Scared. http://mil.wa.gov/preparedness

That probability is far higher than I expected. What is your confidence that the event will be of that magnitude?

Pretty confident. The same earthquake hit the coast in 1700. There is actually a "ghost forest" at Copalis Beach with remnants of the tsunami and earthquake that happened and scholars wrote about it in Japan. More info here: http://www.burkemuseum.org/static/earthquakes/bigone/detective.html -- Steven

After growing up in Seattle, living in California and now living here again, my impression is that earthquakes in northern California are more common and tend to be shallower in depth. I felt about one every year or so (in the 3-5.5 magnitude range). Here, earthquakes tend to be bigger, deeper, felt over a wider area and much more rare. Is this a fair assumption?

It also seems to me we are looking at a longer horizon for a damaging earthquake than northern California, but the earthquake could be significantly more impactful here.

Assuming I'm correct (and you can correct me!), if I spend time in both places, are there differences in how I should prepare for earthquakes given the two locales?

hi Compbioguy: Washington has potential for Deep Earthquakes (like the Nisqually 2001 quake), Subduction Zone earthquakes along the Cascadia subduction zone, and a number of Shallow quakes along faults: The Seattle and Tacoma Faults, among others, have the ability to generate quakes of magnitude 7 or larger, and are very close to the surface. Washington is considered right behind California for states with Earthquake hazards, so there is a difference in the potential impacts, but the San Andreas Fault encompasses a huge amount of the "Hazard" for California, due to its proximity to a large population center. Northern California (at least "hella" far north), is at risk from the Cascadia Subduction Zone, much like Washington, so the Seismic hazards associated with that zone are the same, including tsunami threat along the coast.

As for Earthquake Preparation: The recommendations for within your home are really the same, because the associated hazards are the same. Here are the recommended guidelines for preparations from Earthquake Country Alliance: http://www.earthquakecountry.org/prepare/ -Brian

As Brian said, 2 out of our 3 kinds of quakes are somewhat distant but would affect a wider area than the shallow California quakes.

We also tend to have similar rates of quakes hit our cities compared to California, but we mainly have just the relatively small I-5 corridor, where our quakes concentrate.

California has a vast sprawl of suburbs, many build directly on fault systems, so with their greater number of cities comes greater numbers of quakes.

I'd say preparations are roughly the same, but note that when earthquake early warning is widely available soon, the more distant quakes up here will allow greater warning times than would generally be available in California with their close-in superficial faults.

John

How would you respond to companies building disposal wells for wastewater injection in the Pacific Northwest?

Interesting question! To try to give a diplomatic answer, I would seriously suggest that they look at Oklahoma, which recently experienced a magnitude 5.8 earthquake attributed to wastewater reinjection reactivating old faults. Given the number of potentially dangerous fault scenarios in Washington (see seismic scenarios catalog: https://fortress.wa.gov/dnr/protectiongis/seismicscenarios/index.html?config=devilsMountain.xml), I think it would be important for them to seriously consider and research the location of any wastewater reinjection wells before creating them, and to realize that there are likely many more faults than are currently mapped in the state, which could be affected by this process. -Brian

There has been an injection experiment near Newberry Volcano, which recently ended. As is the case anywhere in the country, such experiments benefit from careful seismicity monitoring, with plans to curtail or cease injection if triggered earthquakes appear.

I expect any proposed injection would attract careful scrutiny from the WS EMD and DNR, and require community input about plans and contingencies. Some fracking in the midwest has skimped on the community input and public information, and is currently a major issue in the cases in which earthquakes have ensued.

John

Whenever I go to Vancouver I'm always in constant anxiety that the big earthquake is going to happen while I'm there (just my luck). Is there any statistics or facts that would help relieve my anxiety?

Also, how far north and/or east would it take until it would be considered 'safe'?

Gala: Hi Aquason. First thing, which Vancouver are you referring to?

This study looks at the impacts of a big earthquake on Vancouver BC https://nees.org/resources/12494/download/10NCEE-001598.pdf

Okay so if the earthquake hits when I'm at work, my plan is to hide in our reinforced walk-in fridge. Would that actually be helpful or just chill or corpses?

Emory: The general recommendation is to drop, cover and hold on. In general, you want to find a sturdy table that you can get out from easily after an earthquake. Going in the fridge, you are at risk for getting blocked and turning into a popsicle before help can arrive.

Maximilian: You can find more info here: http://www.earthquakecountry.org/step5/.

Would you rather be on the street outside a glass tower, or on the top floor of a glass tower, when a major earthquake hit?

Despite the movie San Andreas, I'd much rather be inside the building. Only a small fraction of tall buildings fail.

However, now is a good time to be sure the bookshelves and other detritus perched in dangerous places around your office are secured so the your office is not filled with bouncing stuff when it shakes.

John the seismologist

Maximilian: If you are outside during an earthquake near buildings with glass, then get into an alcove, inside and or under cover to avoid the glass and protect yourself. If you are in a building, drop, cover and hold on under a sturdy desk/table to protect yourself from glass and other objects that could fall on you and injure you. If you don't have something sturdy to get under, then move away from objects that can fall on you and drop, cover and protect your head/neck near an interior wall.

Gala: Inside or outside a building there are risks of dangerous falling debris and you should take measures to protect yourself. Personally, if I had to choose one "I would rather" be inside an (up to code) building under a sturdy table. This video series produced by the Southern California Earthquake Center provides scenario specific guidance: https://www.youtube.com/playlist?list=PLs1gMujRSBY2t7JB4VS-AymFwN-6Lvg20

Do y'all think there's going to be a "major" seismic event out there in the next 50 years? And by major, I mean whatever your personal definition of major is.

Tim and Dave--Yes, somewhere in the world there will be great earthquakes over the next 50 years, probably several

Maximilian Dixon: There is always a chance for a major event. Here is a site that has the USGS earthquake hazard maps: https://earthquake.usgs.gov/hazards/products/.

I live in the Portland, Oregon area originally from S. Oregon. For as long as I can remember we've been warned about "the big one" hitting the region. It's been reported so many times many just tune it out. What are the real possibilities of "the big one" hitting on my lifetime?

Quoting two answers from above:

There is a lot of discussion in the scientific community about the probability of a M9 Cascadia Subduction Zone earthquake in the next 50 years. Depending on who you talk to, this ranges from 10 to 14% or even higher probability within 50 years.

The big one, an M9 along the coast, is estimated to have roughly a 10 to 20% chance per decade of striking. It's a roughly once in 400 to 500 year event, and we're in the window in which it could hit.

P.S. Oregon Public Radio has done an amazing series called Unprepared you should listen to and read:http://www.opb.org/news/series/unprepared/

Chris Goldfinger just upped his estimate of the odds for Portland to include some of the M8 to M8.5 rupture scenarios for the southern half of Cascadia. He also raised his odds for the whole-arc rupture to a repeat time of ~450 rather than ~550 years. But yeah, roughly 15-20% chance per 50 years, within a factor of two.

John

In Oregon it appears we must travel as far as Bend. How much danger is meant by a color of green or yellow?

Gala: Hi Homethinker. Which map are you referring to? If you look at the Oregon Statewide Geohazards Viewer (http://www.oregongeology.org/hazvu/) you can select "earthquake hazard" and the legend shows you expected earthquake shaking according to color. Check it out it's a cool tool.

In the grander scheme of things, there are things you can do to protect yourself and your home where you live currently.

Reducing risks of nonstructural earthquake damage (https://www.fema.gov/media-library/assets/documents/21405)

Individual Guide to on how to prepare for an earthquake (https://www.fema.gov/media-library-data/1408632135401-3d0521fa59d0dd4016e82f08fe7f3732/PrepareAthon_EARTHQUAKES_HTG_FINAL_508.pdf)

What's taking so long?

Gala & Brian: Tectonic plates moves at about the speed your fingernails grow. That said, earthquakes are no-notice events so everyday is earthquake season. Best to be prepared today.

It's a range of the magnitude earthquake is between 300 and 1,000 years. The average is 500 years. It's been more than 300 years since the last magnitude 9 earthquake (happened in 1700) for the Cascadia subduction zone. -- Dave

I'm thinking about getting my multistory, partially brick house retrofitted. How would you go about doing this if it was your house? Would you talk to an engineer or a contractor first? Thanks.

Emory: A good place to start is to check out this homeowner checklist to determine whether your house is properly connected and reinforced to withstand an earthquake here: http://www.safestronghome.com/earthquake/03.asp

Brick chimneys typically need to be braced and anchored. Brick walls are brittle and should be strengthened and anchored. If the brick is just veneer, there are products that can help to anchor it to the wall.

It is a good idea to consult with a licensed engineer, particularly for a multi-story partial brick house. Our seismic retrofit guide is a good place to start that conversation about how to make sure your home retrofit is done right: https://www.strongtie.com/resources/literature/seismic-retrofit-guide

How many days worth of food/supplies should one realistically plan for with the CSZ type earthquake and the Seattle metro area?

What is CERT (Community Emergency Response Teams) and where can I find my local CERT program?

Manuel Lugo: Washington Emergency Management would like the public to stored food and water for 14 days, however is up to the individual to understand their surrounding and the hazard to make that call.

Maximilian: This means 1 gallon of water per person per day. And don't forget your pets needs!

CERT is a great way to get preparedness and emergency training so that you can help your community during a disaster. To find out how to sign up, contact your local emergency management agency or fire department or check this link https://www.fema.gov/community-emergency-response-teams

You can also reach out to us at WA EMD and we can help connect you. Please email me at [email protected].

Would you recommend residents of the PNW move within the next few years? Or move at some time to avoid the earthquake?

Thanks for doing this AMA!

Move? In or out?

We're not likely to have much clue when earthquakes are about to strike, so timing when to hunker down for a few flat weeks in Kansas won't work. We may well have the few seconds we need to take a few simple measures with earthquake early warning in a few years.

Then there are tornados in the midwest, hurricanes on the east coast, lightning, peanut allergies, and other worrisome risks. With a little forethought, the danger of earthquakes is manageable, and shouldn't be a big stress.

I'd recommend tolerating a little risk, funding our efforts to improve safety, staying in this beautiful place.

John

Are experts in various disasters (volcano, tornado, earthquake, etc...) usually more well prepared for a disaster than the average joe or do they slack off like the rest of us? Like doctors who smoke, or fitness gurus who skip leg day.

Some of us are good sources of information, on the other hand, we cannot be too intimidated by the possibilities. My primary plan in the event of a major quake is to hop on my bike and scoot 2 miles over to the seismo lab, rather than hunker down with my supplies at home.

John

I can't/won't speak for everyone on that, but I can tell you for certain that people who work studying disasters and emergency management are excellent sources of information on disaster preparedness :-) -Brian

Is Dante's Peak the greatest movie ever?

I'd call it the one that most accurately (at least compared to other volcano movies) depicts the eruption of a Stratovolcano, and the personalities of volcanologists (Yes, we're all exactly like Pierce Brosnan) but don't recommend trying to drive over lava flows.

So... Yes?

-Brian

I found this map pretty interesting. Do you think landslides would cause a majority of the damage versus damage due to shaking? Would soil saturation play a big role in how much damage would be sustained (would a November quake be worse than an August quake)?

Tim--Most of the landslide hazard in Seattle is concentrated along Puget Sound and Lake Washington bluffs, which is not where the major infrastructure is located. Shaking, particularly from a Seattle fault earthquake, will likely dominate the damage. Landslide probability will definitely be higher when the ground is saturated, though, so November will probably have a higher likelihood of landslides than August.

Would any of you willingly live in Long Beach, WA? Sure seems like those tsunami evacuation routes are a tad optimistic....

bellsy: The hope is that they build more vertical structures like the one in Ocosta (Which we at EMD believe was an incredible development!). Here is an example of some other Project Safe Haven type suggestions: In general, I feel much better having the All Hazards Alert Broadcast (AHAB) sirens, which are activated to warn of approaching Tsunamis, which would give advance warning. Most importantly I would practice my evacuation route. -Brian

Learn more about tsunami evacuation structures recommended for Long Beach, WA in this report: http://mil.wa.gov/uploads/pdf/emergency-management/haz_safehavenreport_pacific.pdf (it's a PDF) -- Steven

Hello, I live in Pharr Texas, it's a small city right in the south-east border with Mexico. 2 months ago, a friend of mine told me that some small earthquakes have been detected near here, in Tamaulipas and Nuevo Leon (Mexico) but I know this area is not a sismic area, do you have any info about new earth movements around this area? because I tried on Google but nothing came up. Thanks a lot.

Maybe check this paper, if it shows up for you:

http://srl.geoscienceworld.org/content/87/4/1022

or this (same paper, a different link)

https://www.smu.edu/~/media/Site/News/NewsSources/EarthquakeStudy/earthquake-study-17may2016.ashx?la=en

John

Why don't you make an easily found map of the national earthquake zone levels overlayed with cities so people can locate safe and dangerous cities much more easily?

Hello homethinker! There are a number of resources which can help people out with this. In Washington I would suggest checking out Department of Nartural Resources Interactive Hazards map, which allows you to enter an address and overlay it with a variety of geologic hazards (Shaking levels, Landslide threat, liquefaction hazards, tsunami inundation threat, volcanic hazards...) You can find it here: https://fortress.wa.gov/dnr/protectiongis/geology/?Theme=natural_hazards In addition, I would suggest the USGS Earthquake Hazards program maps, which have a general Earthquake threat for the entire country: http://earthquake.usgs.gov/hazards/products/ -Brian

Are there miniature, imperceptible equivalents of tsunamis (like their are earthquakes)?

Tim and Dave--Definitely. The tsunami from the 1964 tsunami from Alaska was only a couple of inches high at Seattle.

Hi Suaveitguy. Yes, because of the large size of the ocean there are many every day, but our underwater network of sensors is not nearly as developed as our on-land one. Tsnuamis are caused by displacement of volumes of water, which create waves that travel through the ocean. Small movements of the plates underwater, such as mid-ocean ridges would cause some of these. In addition, any underwater explosions, volcanic eruptions (off the coast of Hawai'i for example) could cause these disturbances in the water: However, all of these sources would displace a significantly smaller volume of water than a Tsunami though, and are not usually noticeable. -Brian

In the context of the earthquake early warning system (EEW) being developed along the west coast, if a seismic event occurs along the Cascadia Subduction Zone, how equipped is / will be the network to issue precise information when an event is far offshore? Further, will the EEW system be able to give real-time tsunami warnings for coastal communities (i.e., tsunami height, direction, etc.)?

The subduction zone is a primary reason for building the EEW. We would see the first seismic waves on our nearest instruments along the coast before the earthquake has spread far nor built up much energy.

Anywhere from 30s to 3 or 4 minutes of warning should be possible for people in the Puget Sound, Vancouver, or Portland.

John

Thanks for the AMA! I had three questions:

1: I had heard that in the past, possibly the last "big" one, that Alki's beach area in Seattle either rose or fell by around 5 feet of elevation. Is that true? If another big one hit, could we end up in a scenario where Alki goes up further, or slips beneath Puget Sound?

2: Could an earthquake actually cause Mount Rainier to trigger in any way?

3: I know the Seattle Fault runs sort of along the north edge of West Seattle/through the north end of West Seattle, across Elliot Bay, and then runs straight through downtown toward Lake Washington. Is this a subduction fault, or a side-by-side one? If that fault had a major event, general destruction aside, what sort of permanent geological/land changes could it cause, realistically, to the city?

Thanks!

1. The beach was raised by an earthquake on the Seattle fault, not the coastal fault that hosts the M9. A coastal quake would no readjust the Puget Sound coastline much unless there were local landslides.

2. An earthquake could trigger Mount Rainier, either to erupt or to generate a lahar, but the chances of triggering a serious event are quite small.

3. The Seattle fault is a "thrust fault". It is not the subduction fault, it is a more minor fault in the crust of the Earth. It is not a sideways-moving fault, a "transform" or "strike-slip" fault. A big event on the Seattle is rare, but could be catastrophic for downtown Seattle (and Bellevue, etc.). We had one back in 900AD.

John

Thanks! Could the Seattle Fault potentially drop Alki back down? Asking in case I ever get rich enough to buy a house down in my favorite neighborhood.

Faults generally move just one way, but in fact the Seattle fault zone movement is several miles wide and complicated, and so it is hard to predict the exact pattern of deformation we would see at the surface.

John

Do you have info/maps on how the Big One might impact Snohomish County? Specifically Everett.

I would suggest checking out the Seismic Hazards Catalog for information on expected impacts of the disasters: http://www.dnr.wa.gov/geologyportal (now fixed)

-Brian

Added a new link since the previous one didn't work. FYI http://www.dnr.wa.gov/geologyportal

Wow, great ama! Is there any concern over Mt. Baker (or any of the other large Cascades) during seismic activity?

Thank you! There have been a couple of rare and isolated cases in historical times where Earthquake waves have led to changes in underground activity, such as directed surface waves from the 2002 Denali Earthquake (M7.9) causing unusual geyser and hot spring activity at Yellowstone National Park. ...the 1980 eruption of Mount Saint Helens was associated with an earthquake, but this earthquake was located on the volcano itself, and Saint Helens was already highly unstable due to a growing magma chamber along it's flanks.

For comparison, to the overwhelming majority of earthquakes, many earthquakes occur daily near volcanoes along the Pacific "Ring of Fire" (like the Cascades), but rarely are these directly associated with causing any activity at nearby volcanoes.

...So, wouldn't say it's impossible, but comparing the couple of isolated incidents on the historical record, it seems very unlikely that an earthquake would cause an eruption of one of the Cascade volcanoes, so I would not say there is any "concern." Hope this helps! -Brian

How far east do I have to go in SW washington to be in a safe zone?

Tim and Dave--If you are still in SW Washington, you are not far enough east to beyond the ground shaking from a Cascadia subduction zone earthquake. Go to http://www.dnr.wa.gov/geologyportal and open the Scenario catalogue. Look up the Cascadia scenario.

Maximilian: This depends on what type of safe zone you are referring to and where you are at that moment. For an earthquake, you will want to "Drop, Cover and Hold On" http://www.earthquakecountry.org/step5/ . For a tsunami you will want to get to higher ground as soon as possible. Go to this DNR web site to get the latest tsunami evacuation and inundation maps: http://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/tsunamis .

As we've seen from last weekend's "OMG End of the World!" fizzleout, the region loves to overstate weather/nature apocalypses. I've been hearing about impending The Big One, the one that will level Seattle and send us back to the stone age for as long I can remember, that it's kind of lost it's impact. So is it really still a thing and when should I expect it?

Hi Retiredtype40. Indeed, the media does tend to sensationalize things, but it is more as a way to make sure people are prepared than anything else: Weather models, due to all of the tiny currents in the atmosphere, even with all of their advances still have a high chance of being inaccurate; that being said, they are far more accurate than our current ability to actually predict earthquakes with a time and date. As for whether "The big one" will occur or not, the prediction of this event is based on geological history and evidence of past events. in addition, our gps network and seismic stations show that the plate is continuing to move beneath us, and has been locked in a position that will allow it to slip with enough energy to cause a high magnitude earthquake: so yes: The Big One is still due, but it is impossible to predict the exact time. This is why it's important for everyone to be prepared. ...Not to say we're not hoping to make some huge breakthroughs in Earthquake prediction soon. THAT will be big news when it happens! -Brian

How close is the prediction technology to operational? I heard about the California prediction from last week, but it looks like that kind of fizzled out, so clearly it's not there yet. Is the technology pretty close? A ways off yet? Almost there but needs fine tuning?

Actual Predictions are not something that we've developed yet. What was happening in California was a statement that likelihood of an earthquake, was slightly increased by a tiny percentage for a short period of time. This was based on seismic activity, not based on any type of technology. The closest Technology that we are working towards at the moment is Earthquake Early Warning, which could provide seconds to minutes of warning before the strong shaking in an earthquake. This is based on detecting the P-Wave, or Primary wave from the Earthquake, which travels faster, and giving warning about when the secondary wave will arrive (which travels slower, but shakes the ground more strongly). We are still a couple of years off from this technology in Washington, but it is in development! See http://www.shakealert.org/ for more detail about the West Coast's effort to develop this technology. -Brian

The California statement was not a prediction. It stated that the probability of an earthquake on the San Andreas fault was temporarily slightly increased. Prediction is still not feasible.--Tim

Should I buy earthquake insurance in Seattle?

Really depends on your situation. Older buildings are less good, URMs (unreinforced masonry) is less good. Simplest is to bring over an engineer, maybe a house inspector, to give you an opinion. Oftentimes problems are best addressed by a little retrofitting to fix problems rather than buying insurance for known issues.

J

Have you modeled a Cascadia megaquake-caused Lake Washington seiche? If a significant concern, would Puget Sound respond analogously?

Aggeliki Barberopoulou worked on seiches in Seattle for her PhD thesis at UW. She published several papers on the topic. Try Googling her--Tim

The seiche directly from the shaking from the quake would be tiny, maybe some currents of concern, but the water wouldn't rise or fall much. A bigger concern would be waves caused by landslides into Lake Washington or the Puget Sound, which then would depend on exactly where and how big might the slides be.

John

Maximilian: Great question. We'll look into this.

I am ready for the Yellowstone Mega Eruption to happen and swallow up Hillary Clinton and Donald Trump. When can I expect that to happen?

Some time in the next million years, maybe. No reason to expect it sooner rather than later.

John

So when my dad was on the FEMA board for the schools district up here back in the 1980's they said then we were 25 years past due for a major 7.0+ quake at anytime and if that happens all hell breaks loose, plus we are in no way ready or prepared for one if one does happen. I know we still are not prepared to the level we should be still. My question is do you think a major quake like 7+ could trigger Mt. Rainer to blow? How close are we to this scenario possibly happening?

Lahars are also a problem from volcanoes, and earthquakes conceivably could trigger either, but it is unlikely. I'd worry more about earthquakes than volcanoes unless you are in the lahar path from one of the volcanoes.

Also, we are not "past due". The danger changes little from year to year.

John

Do any of you have a regular presence on Reddit? I've sent an invite to join the moderation team over at /r/cascadianpreppers - I imagine that can be a useful sub for academics, responders, agencies, and the public to all mesh ideas. Anyone interested?

Will pass this on to John Vidale, the state seismologist. -- Steven

Can't guarantee I'd do much, but I could take a look. I go by the obscure Reddit name of JohnVidale, how does this moderation work?

Moderation is pretty easy. You just sit back, wear shades, look cool, and accept money from the Democrats.

I'm kidding. There's actually no real work in moderating a sub like /r/cascadianpreppers - it just gives you the ability to remove comments and change stuff in the subreddit, it's stupendously simple. I'll send an invite to /u/johnvidale

Honestly the main thing the sub needs is just someone posting more content: any relevant news article, published report, event, ect... anything about the CSZ can be run through that sub. More content = more active readers = more discussion about the event = more promoting of the sub = more content.

I clicked something, not quite sure what.

John

It looks like the request is still pending. On the upper right of your browser (when you're logged in as johnvidale) you should see the little reddit icon in reddit or a private message from me, click that. You should see a "join" option. There also might be a delay, I'll ping your other account tomorrow if it's not worked out.

Ok, think I did it this time. But I probably won't be very active.

Would you be willing to hold meetings between state and federal geolologic and FEMA agencies to make a flow chart available to the government employees, so that if I googl USGS and only water conservation comes up in the search, that the water employees can know where to direct earthquake questions?

Maximilian: It sounds like this would be a great question for Google.

wasn't there a scientist that claimed to use clouds or cloud formations to predict earthquakes? or did i fever dream this on a nyquil binge?

I wouldn't be surprised if that's something that you've heard (NyQuil or not). People have suggested a large number of ways to potentially predict Earthquakes, but there haven't been any verified by recognized scientific processes yet... Still people have tried testing a wide variety of possible methods.

We'll keep trying though: Earthquake prediction is considered the "Holy Grail" of Earthquake science, so as soon as scientists make some sort of discovery, it will be all over the news for sure. -Brian

Mr. Vidale, why don't you take earthquake forecasters more seriously and why discount their work? I rely and trust Dutchsinse on YouTube way more than you guys at pnsn who sometimes don't report earthquakes in your zone. He's surprisingly accurate and you guys could be way more effective if you researched and tried his methods scientifically rather than attacking him? I live in the pnw and don't trust your guys work as much as Dutch. Please please give it some thought, it could save countless lives, which should immediately grab you're attention. Use science to disprove him please, or try out his methods

Dutchsinse!? He says the Earth's core is plasma, he says sightings of bigfoot mean there will soon be "false flag" incidents conducted by the global conspiracy of whatever. He has never checked whether his predictions work, and they are based on mistaken ideas.

As you might imagine, he has absolutely no credibility.

If he ever tried to keep track of his predictions and evaluate them, he would realize their value.

John

And we report all events. Dutchsinse can't figure out that events way offshore are extremely common, and beyond some distance outside our authoritative area, and in fact, outside our ability to report them.

We tell him this over and over, and yet he keeps repeating the same "hiding events" claim, either from inability to understand or dishonesty.

John

He does check if quakes he predicted did or did not hit, and he's on the money more often than not. Look he's on to something and you don't take it seriously. I just think that if there's a chance that you can be as accurate as Dutch is it's worth looking into. But claiming that certain things are impossible such as deeper earthquakes influencing shallower earthquakes and earth's core is plasma is kinda stupid, from a scientific perspective. Most people working in the field of science who claim things are impossible are most always proved wrong later down the road. I just wish that you guys would keep an open mind and look into everything that could move the ball forward with understanding earthquakes. I'm positive If you guys opened a dialogue with each other and kept an open mind you both would learn something. His years of practice and experience forecasting earthquakes should be of value you.

By all means show us a record of his predictions and their success rate. That remark was tongue-in-cheek, I know he has never monitored whether his predictions work or not.

I've watched many of his videos, both before and after his claimed successes, and am unimpressed. I'm mostly impressed with his ability to mislead himself about how he is outthinking all the scientists in the world on a wide range of topics despite knowing no math and almost no Earth science.

John