Public sentiment is marked by significant fear, skepticism, and frustration regarding the potential mega tsunami threat from the Cascadia Subduction Zone. Many commenters express a lack of trust in governmental preparedness and share personal stories that highlight the urgency of individual and community readiness. While some dismiss warnings as fear-mongering, a strong undercurrent of concern for safety and the need for actionable preparedness strategies prevails.

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Just wanted to add a couple comments from the Pacific Northwest Earthquake Discussion Group on Facebook, since a lot of scientists are in there and will comment on these papers! Someone posted asking about the paper and how it related to another recent study.

Harold Tobin (PNSN director and one of the study authors): 
&gt;I wish the OBP reporter had called us for a little more context and explanation. The new research paper on the purported “megasplay” fault did find that there is not such a splay fault in many places from north to south all along Cascadia. This can be good news for the time elapsed from earthquake to tsunami arrival at the coast, in those locations. But there’s also evidence of slip to *other* splay faults farther offshore, which will contribute to tsunami hazard in ways not fully calculated yet. The bottom line is that the most likely case (not necessarily the maximum 2500-year return case) tsunami scenarios may change some, but it’s not clear if they’ll be better, worse, or not much different for each place along the coast."

Chris Goldfinger (marine geologist/geophysicist who works on these same topics):
&gt;There are two things at play here 1) research papers that stick closely to the data they use, and 2) tsunami oriented models that are generated in worst-case scenarios for public safety.   The newer paper is in the first category, the existing models for Oregon in the second.   Also the title of the paper might lead one to believe that the megasplay fault does not exist.  There are multiple interpretations out there, and even in the new paper, the fault is there, just not margin wide, and even that is not a new interpretation.   So what is actually new?  Not that much really.  A concensus view by the tsuanmi working group working on unfied models fo rthe three US states agreed to lower the probability for megasplay rupture from relatively high to a lower value, and all were in agreement that the original values were too high.   However, in the interest of public safety conservatism, the models including this type of splay will remain, just at a lower logic tree value because what it really might do remains an open question.   One of the reasons that this is not clear cut is that there are things known as "blind thrusts", that may well have earthquake potential, but do not show strong evidence of surface or shallow rupture.  The Coalinga earthquake of 1983 is a good excample of a blind thrust earthquake with no shallow rupture.   Lack of surface rupture would have little to no effect on tsunami potential because thaat is a longer wavelength flexure of the upper plate.  These are the issues that went into the more conservative view of tsunami potential for Oregon.  The problems are complex, and I wouldn't necessarily take each new paper as good news or bad news, they have to be considered with the body of knowledge as it exists.

alienbanter

I work for the Oregon Department of Emergency Management and come across a lot of information on Cascadia. I have a personal website (separate from my work duties) that I created to help provide the public with information I learn in my day-to-day. Just free info for anyone interested: [Surviving Cascadia – Pacific Northwest Earthquakes and Tsunamis](https://survivingcascadia.com/)

SurvivingCascadia

The tsunami might be not so bad, but the lost access to federal aids certain will make the situation more disastrous than it would have been. 

Fuck Republicans.

whk1992

I feel like the bigger danger would be the lahar from Rainier should that ever go.

MassageMeow

Well this is a great start to my Wednesday

jazzlike-sounds

Tsunami estinates are murky but it could go far inland, especially where basin effects exist. The EQ at design level would be felt hundreds of miles...actually they easily register around the world for many loops...actually feeling it would be couple hundred miles but highrises and large diameter tanks would slosh several hundred miles. Early last year highrises in miami were evacuated due to a M7.7 EQ near cayman islands as the surface waves came thru some 850km away...little different than cascadia but you get the gist...it isnt going to be localized damage or impacts. https://www.dnr.wa.gov/news/new-study-shows-impacts-cascadia-tsunami-puget-sound

https://i.imgur.com/LdTeIVs.jpeg

rb109544

The tsunami will only affect the actual coast within several miles at the most - even 10 miles would be a lot. (Edit: you could get effects still in places like the Puget Sound.) Shaking would be felt quite far inland. Here's an example simulated ShakeMap for a M9 scenario: https://earthquake.usgs.gov/scenarios/eventpage/cszm9ensemble_se/shakemap/intensity

I live right on the Oregon Coast. It's safe to assume it will look a lot like Japan in 2011. 
One big difference though is in Japan they regularly run drills and have construction methods that help mitigate damage. We don't have a lot of that here because tax cuts and hubris.

Wildfire9

I'm by no means an expert in any shape or form, but my (bad) understanding was that the scary tsunami scenario would be caused by seafloor deformation as the subduction 'pops' it back rather than the standard EQ 'slosh'?

Tangled_Design

Any tsunami may stay local for 10-15 miles inland.  However we need to remember the rivers and streams. For the Columbia River runs in-between the States of Washington and Oregon will be affected by the tsunami. The cities and towns along  the rivers and streams will be flooded. The closer to the ocean the more severe the impact will be.
As far as how far inland on the rivers and streams will depend on the size and strength of the earthquake causing a tsunami will be. The Willamette River that runs into the Columbia River will also rise flooding Downtown Portland and the surrounding communities.
The swarms of earthquakes that are happening in PNW is just a reminder that being ready for a natural disaster is not to be ignored. Also to mention the Cascade mountains are unsettled. More earthquakes detected are small but we can never be over prepared for a natural disaster.
Recap - Earthquakes in the West and more from Cascades are again small, but never underestimate the power of nature's fury!  1980 Mount Saint Helens Volcano.
This was a powerful event  I watched as it happened.
To this day it is still very fresh in my memories! I am as ready as possible to be ready. Please be smart and also be ready.
The survival of and  your loved ones will also need to survive.PLEASE, PLEASE include all pets. The animals will have to suffer harder than we humans will. They won't understand what is happening. Desperate, hungry, in pain and separated from family will hardship your animal/s and family. God Bless all to humanity.

Brooklyn-68

My husband was part of ETF when we lived in the PNW. Certain areas are expecting to no longer exist in the county where we lived. In addition, the city we lived near, is expected to have a wave hit the bluff near the tracks, and the water will slosh around back and forth for hours. I didn't live in Seattle, but I know the subduction zone goes right under the city. The scientists were not discussing that area in the meetings my husband attended.

No-Error8885

All conjecture as no one really knows until it happens. Until then folks ..

mikkokilla

I don't think it will reach inland much lot of coastal mountains to buffer the valley floor from the initial water seige of a tsunami when the cascadia finally decides to give us the rude awakening it's waiting too give us hopefully I won't be in California or anywhere near the pacific coast when it goes finally move

Stormrider2025

It will be devastating east of I-5 too. You can find earthquake shaking maps for each state along the Pacific coast. They say where the earthquake will be felt and to what severity. 

In Oregon it's called the DOGMI map. Here the earthquake will be very destructive east of I-5 clear across the Cascades. They don't expect most of the roads and bridges to survive there and that the Willamette Valley will be cut off from transportation for months on all sides. Depending on the geology of the area you might be in a heavy hit area but on a geologic 'island' where it doesn't shake as much too. Find your state's map for the best info.

ItsNotGoingToBeEasy

Well the Oregon coast will be gone to the cascade mountains. Portland Oregon would flood because of Columbia river gorge and Willamette river   Seattle would be gone So I’m guessing California coast including LA will be destroyed and beyond LA will be the new coast  Oregon coast will be right over cascade mountains. It’s will be bad 

Regular-Song-6799

I worked for one of the major corporations in the area in planning for this particular disaster, in coordination with ODEM and FEMA.

Their data says when that earthquake hits, everything west of the 5 will be gone (0% chance of recovery) between the quake (main and aftershocks) tsunami, and ground liquification.

Most of the metro area will be rubble and or flooded due to the rivers being pushed inwards due to the tsunami.

For the area it’s predicted to be as close to an apocalyptic event as you can imagine. 

Word2DWise

Just how will it affect the cost? Say in Westport wa?

cancer5150

Read the 2015 New Yorker article.

https://www.newyorker.com/magazine/2015/07/20/the-really-big-one

Motor_Ad_9028

It’s a good reminder. Go get a pallet of water, first aid kit, emergency radio. Along with food for a week, 3 days of it in a bug out bag and you’re more prepared than most.

Honestly, it’s little emergencies we should worry about most. Keeping a wool blanket, bit of food and water in your car and a flashlight would be a lot more likely to get used than earthquake prep

BrightAd306

I used to live on 40th Street and 8th Ave, in the U-District. Two blocks east of I-5. 

I woulda survived!

MeaningNo860

I live in an area near Seattle where we get a few power outages each year.  They may be a few hours, and a couple of years ago one was about 3 days. The number of people prepared for even those short outages is sad.

Sufficient-Wolf-1818

Fortunately that isn’t how earthquakes work. The whole “overdue” thing is a way over simplification, earthquakes aren’t predictable like that. It’s based off of the distance between past earthquakes, the problem being, earthquakes don’t follow patterns. Especially since the factors that cause earthquakes have changed a great deal since the last big one. People who tell you an earthquake is “overdue” have no idea what they’re talking about and shouldn’t be taken seriously. Btw the “due date” is a window of about 1000 years.

mooshroom333

No. Because a natural disaster doesn’t suddenly become more likely just because an unrelated one happened.

[deleted]

It’s been looming for decades and decades

CascadesandtheSound

As someone with extensive emergency management experience, and access to all the fun documents and studies (everyone does, they're all public information, just a little easier for me because it's need-to-know info), the projections for a worst-case cascadia subduction zone event pretty much leave most of the Seattle metro area in shambles. Most major cities not inhabitable for over 6 months if not closer to a year, and expected death toll in the 10s of thousands. There's also an expected PERMANENT  loss of population. People who move away and never come back - and up to a decade before life returns to 'normal'...

The most recent relevant documentation is here..  [https://mil.wa.gov/asset/62bc6bf87b6dc](https://mil.wa.gov/asset/62bc6bf87b6dc)

Plan is to evacuate Seattle across the sound to the Olympic Peninsula and stage rescue/recovery efforts from there. Most bridges will be damaged and impassable, and large areas will be 'helicopter only' access, where downed power lines, and debris don't block them from landing.

You will be on your own, for most of such event, and weeks after. No police. No fire. No groceries. No sewage. No water. You're gonna go back to the stone age.

While the initial death toll from the event itself is said to be relatively low, quite a few more will die in the aftermath due to lack of medical care, food, water, and sanitation, not to mention things like fire..  The vulnerable (elderly) populations being hit the hardest, of course.

You need to make alternate plans to get home, or to somewhere other than home, if you have a bridge between your house and your work - it won't be there or will be structurally unsound.

You NEED to have your preps on you. A 'get home' kit should be with you everywhere you go. 3 days of food/water, small tools, pry bar, emergency blanket, changes of clothes that match the season, respirator/mask, etc will all fit into a small backpack. In the event you can't make it home, you need to have an alternate plan of somewhere to go. You need to have a plan with your family.

Phones will be down, and there will be virtually no means of communication outside of satphones, starlink, and 2 way radio (amateur, GMRS, etc). The current radio system in use by King County will go offline, leaving only very limited range for responders in the field, who will be worried about their own families - it happens..

This is a 'prepared to be on your own for weeks, if not months' thing.. Not a 'Power went out for 2 days' thing.

Stockpiling water, dried goods, canned goods, etc is super easy.

For people in the Seattle area, LDS runs a storehouse in Kent that's all for long term food storage. They have the lowest prices in the area, much cheaper than other places ( even online), and you don't have to be a member of the church to shop there.

You can fashion a toilet out of a 5 gallon home depot bucket, and a trash bag. Even better if you buy a HUGE bag of pine shavings, like hamster bedding - it's an impromptu composting toilet. I had to daily use one for a while and a single bag (poo, wipe, toss shavings over it, repeat) lasts about 2 weeks. The bedding absorbs moisture and odors, and keeps things contained. When full you dig a hole and pull the bag out and bury it. This is for SOLID WASTE ONLY. Do no do #1 in your poo bucket. Go piss against a tree or a pop a squat (for the ladies). You do not want to mix liquid with this or it'll turn into sewage and become a smelly bacteria infested pit.

OldBayAllTheThings

HighColonic

  
Estimated impacts include the following:

● Earthquake

o Building damage – 618,599 buildings with moderate to complete damage

o Schools – 2,026 schools with moderate to complete damage

o Hospitals – 100 hospitals with moderate to complete damage

o Critical facilities – 2,777 critical facilities with moderate to complete damage

o Total economic losses – $134 billion

o Utility system economic losses – $15.9 billion

o Transportation system economic losses – $3 billion

o Job/wage losses – $6.2 billion



● Tsunami

o 27 counties, including areas impacted along the Pacific Coast, Puget Sound, and

Columbia River

o At least 17 tribal nations impacted

o 453 miles of impacted Pacific Ocean coastline (296 miles in Oregon, 157 miles in

Washington)

o 1,810 miles of impacted Puget Sound coastline, including the San Juan Islands

o 10- to 30-minute warning for coastal areas

o 90- to 120- minute warning for Puget Sound areas

o All seaports on the Pacific coast at risk of sustaining complete damage; seaports

along Puget Sound and the Columbia River (west of the I-205 bridge) at risk for

major damage

o Multiple tsunamis 10 to 12 hours after initial earthquake; first wave may not be

the largest

o Wave heights that vary from 3 to 80 feet

o Aftershocks of M7.0 or greater that could generate additional tsunamis  


The most recent relevant documentation is here..  [https://mil.wa.gov/asset/62bc6bf87b6dc](https://mil.wa.gov/asset/62bc6bf87b6dc)

SchufAloof

If it happens when Trump is President, we won’t even get aide in places that didn’t vote for him, something to keep in mind.

PleasantWay7

Nope, don't care at all. If it happens, it happens. There are no preparations to be made for a +9 magnitude quake.

liannawild

What is the point of this post? To state your anxiety?

SpicyArms

Chief_Kief

It will suck yeah, but we will be togetherness. All feeling the same shaking suckyness. It’ll be a time for community that we haven’t seen in decades

Literally yes! I was thinking that this week. So sad for NC.

gypsygeorgia

Yes! When I worry and stress about the earthquake I noticed that I keep us all safe one more day.

herpaderp_maplesyrup

skysetter

[https://youtu.be/ygH4hYfE9mg?si=3eQjCr5SreNak4nn](https://youtu.be/ygH4hYfE9mg?si=3eQjCr5SreNak4nn)

The 9.0 simulator on youtube......

Significant-Repair42

I live about 3/4 mile east of I-5 in the south sound… guess I’m good! Bet seriously, yes it stresses me out.

TempoMortigi

That seismic zone seems to have a capacity for the largest most violent quakes humanity has ever known in recorded history. 

We’ve got Tōhoku, Sumatra, Chile, and Alaska as the big boys in the last 100 years. Tōhoku was very ready for quakes and tsunamis and they lost 20k people. The Pacific Northwest is not ready. They are dancing with the devil saving tax dollars on disaster preparedness just hoping that it’s not their generation that gets the bad dice roll.

bunkerbash

I live in Southwestern Canada which happens to be in the Cascadia Subduction Zone.

We have been warned that some day the Cascadia Subduction Zone faultline will someday snap resulting in a magnitude 8 or 9 megathrust earthquake and tsunami.

Sadly it will be the worst natural disaster in both Canadian and American history with massive damage, loss of life and injuries and it will take years for a full recovery.

I always wish that it will never happen but sadly it is going to happen sometime in the future.

Apprehensive_Idea758

*Great Earthquakes of the Pacific Northwest*    
https://youtu.be/UJ7Qc3bsxjI     

**50 Year Probabilities**    
Cascadia Trench Full Rip 9.0:   14%        
Cascadia Trench Partial Rip 8.0:   25-40%    
Seattle Fault:   5%        
Puget Sound Shallow Fault 7.0:   15%       
Puget Sound Deep Fault 7.0:   84%

holmgangCore

Lots of good info here:  r/CascadianPreppers/

attorneyatslaw

[I read this a few years ago.](https://www.newyorker.com/magazine/2015/07/20/the-really-big-one)

I think I won't be moving out west anytime soon.

booksgamesandstuff

Good site. You might add info on strengthening homes ([bracing &amp; bolting](https://www.earthquakebracebolt.com/)) and also securing things inside the home, like [water heaters](https://www.earthquakecountry.org/step1/waterheater/).

Cherimoose

I spent 20 years on the southern Oregon coast where the fault is closest to the shore. Everybody who lives there has some kind of plan what they will do. But the hard reality is you can't really prepare for a mega-quake.

And if it happens at night, most everyone along the coast is going to die... It will scour the ground right down to bedrock. You can't run during a big quake. You can't drive either. The roads will buckle. Rock fall will block the rest. And subsidence that occurs during the quake may bring the water in even before the tsunami forms... I know places where the land sank 30 feet in 1700.

Japan has the same offshore mechanics but in reverse. And, their fault erupts more regularly than the Cascadia fault. Therefore, more accumulated strain it has, the more dangerous it becomes.

When Cascadia lets go, it's going to be "biblical"...

If a volcano eruption happens first then ya something might happen

Far_Out_6and_2

I expect there to be as much shaking footage and tsunami footage if maybe not more than the Great East Japan Earthquake on March 11, 2011 if the Cascadia megathrust is to happen this decade.

probium326

It kind of surprises me that this is a new conclusion, when the ghost forests caused by subsidence are one of the main clues that led to the pinpointing of the origin and date of the last earthquake and Japan's "orphan tsunami" in 1700.

clintj1975

I recommend reading “Full Rip 9.0” by Sandi Doughton, and watch Erin (Wirth) Moriarty who explains the earthquake potential and mathematically modeled shaking for Bainbridge Island residents: 

https://youtu.be/EHCZoHTrr94

mattaccino

Didn't they read that New Yorker article from like 10 years ago?

SomeKindOfOnionMummy

I live in the Puget Sound area. I can’t remember what video I watched but there is a video showing a simulation of how the tsunami could hit the Seattle area. It was really interesting. Apparently Portland is of concern because they aren’t as prepared though I can’t remember the details.

sparkyhedgehog

There’s this. Plush choice beach front. 1 way in/out. 39 feet in “elevation”. Ocean Park WA.

https://preview.redd.it/5dnx6d0j5sxe1.jpeg?width=1170&amp;format=pjpg&amp;auto=webp&amp;s=84e39be34226b78d297e6a78275b92a0adc83146

NOVA-peddling-1138

Randall Carlson talks all about historic floods from cataclysms on his YouTube channel.

TexasPrincess1

Thanks alot. I live in westport and live in constant fear. While I'm glad I'm not ignorant to the situation reading threads like this dosnt help.

If you live in the PNW, this is drilled into you.

Smokey76

Fear mongering to sell news stories. Everyone already knows the horror of Magnitude Nine quakes.

peter303_

Bring it! This time line is a mess right now!

MLCarter1976

Scientists have raised alarms about a potential 100-foot mega tsunami threatening the US West Coast from an overdue earthquake.

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