1700 Cascadia Earthquake
en.wikipedia.org
en.wikipedia.org
That's the next earthquake.
https://pnsn.org/blog/2020/01/27/getting-ready-for-the-next-...
I saw them perform it at a concert in front of the Space Needle. Really felt I was tempting fate there.
> fema projects that nearly thirteen thousand people will die in the Cascadia earthquake and tsunami.
From the rest of the article, it seems that this estimate of deaths is too low by an order of magnitude. More people died in the Fukushima earthquake, and that is in a country that is probably the most earthquake ready country in the world.
If you only have 15 minutes from the start of the earthquake to when the tsunami rolls in, given the density and the lack of preparation, I could easily see several 100 thousand people perishing if not a million.
With the exception of the international district, all the low-lying areas are industrial in nature.
> As for casualties: the figures I cited earlier—twenty-seven thousand injured, almost thirteen thousand dead—are based on the agency’s official planning scenario, which has the earthquake striking at 9:41 A.M. on February 6th. If, instead, it strikes in the summer, when the beaches are full, those numbers could be off by a horrifying margin.
Thirteen thousand sounds like a best case scenario. If it happens 4th of July weekend when a million people are on the beaches all up and down the west coast, that could cause orders of magnitude more fatalities.
In this sample evacuation map for Ocean City WA, the higher ground is within half a mile of a good chunk of the coast, and nearly all of the coast is a mile from higher ground. https://www.dnr.wa.gov/Publications/ger_tsunami_evac_oceanci...
Also, unlike in California or the East Coast, these are not quick jaunts to the ocean.
It’s likely no one state adds up to 1 million people, but collectively people at in or near pacific ocean in the US, Canada, and Mexico are at risk. So, if you want to understand the risk from such an earthquake you add everyone together.
in particular this hedge:
> Perhaps no line in the entire six-thousand-word piece attracted as much attention as this declaration by Kenneth Murphy, head of the fema division responsible for Cascadia: “Our operating assumption is that everything west of Interstate 5 will be toast.” The first important thing to note about that remark is that, needless to say, Murphy really said it, and stood by it in the fact-checking process—so, clearly, fema is anticipating that the region will be in very grave shape.
> That said, “toast” is not what you would call a precise description, so let me be more specific. What Murphy did not mean is that everyone west of I-5 will be injured or killed; fema’s casualty figures, while horrifying, amount to under one-half of one per cent of the population of the region. Nor did he mean that every structure west of the interstate will fail
If including "a million buildings destroyed" (or whichever other part you felt you couldn't include) would make your comment seem less devastating, it just isn't that devastating. It's fine. Representing things accurately is more important than... whatever we were hoping to achieve there. Seeming cool for knowing the original article was BS, I guess?
It's a good article! I don't think it's BS. I might think that if I read your partial excerpt, but that's a problem with the excerpt.
https://www.usgs.gov/news/volcanoes-vineyards-new-geologic-m...
For instance, look at page 3 of the pamphlet:
https://pubs.usgs.gov/sim/3443/sim3443_pamphlet.pdf
To the west of Portland we see Dark Gray which is Basalt (if you've ever driven through the tunnel and up and over the west hills to the western suburbs of Portland, you have driven through the basalt region) and then there is a big light yellow oval that is labelled Tualatin Basin. What is the light yellow according to the legend? It is surface deposits. Long ago this was a basalt bowl. Then a giant flood came down the Columbia river gorge and dumped hundreds of feet of clay silt into the bowl. When you are standing in Beaverton, Hillsboro, Bethany, etc. you are standing hundreds of feet above the original valley floor.
Now look at the map again. The basin is pretty much all to the west of I-5. If you live in the basin you are screwed when the big earthquake hits (the one exception is that hill of basalt rising like an island in the middle of the basin - that is Cooper Mountain, it's no coincidence that the houses on top of Cooper Mountain are where the rich people live). What is going to happen is the earthquake waves will come in and bounce off the basalt on one side of the bowl and reverberate back to the basalt on the other side. The waves will go back and forth in the bowl and liquefy all of that old clay silt. Just like this:
https://www.oregonlive.com/today/2016/04/really_big_one_puli...
This article and that image flashed through my mind when not more than a few weeks later, I found myself sitting on the 4th and uppermost floor of a 100+ year old brick building, precisely where that fault line was drawn, as the floor started bouncing, then swaying, then the ceiling lamps were swinging back and forth so violently that they were hitting the ceiling on either side, and interior brick walls started to give way.
I worked in that building for another year and a half after that February 2001 6.8 magnitude Nisqually Quake[1], and every time a truck bounced down the potholes of 1st Avenue South, and the office floor bounced, my palms would sweat.
When a big one hits Seattle or the Midwest is when you’ll see untold damage. Just compare bridge pillars in various parts of the country.
I am talking about the Cascadian Subduction Zone letting go which happens every 200 to 1200 years (41 times in the last 10000 years). The last time this happened, in 1700, there was a 9.0 earthquake, a 100 foot tsunami and the coastline dropped several feet.
There is about a ~10% chance this will happen again in the next 50 years. If it does, large areas will be completely unprepared and a very large number of people will die.
Couple other quakes happened since I moved here, but I was out of town for one reason or another. I even was in eastern France when they got hit by an extremely rare earthquake in ~2004.
Nisqually: .3g
Northridge: 1.82g
At the time we were told to head for the door frames which was like trying to run in a bounce house.
(For myself, best I can figure, I was on a bus and didn't notice a thing.)
Here is the best attempt I've seen so far to novelize what will happen in Portland. While obviously speculative, it's all very much based on the evidence at the time and I think does a better job of describing what will happen than just reading the dry (and usually incorrect because they assume supporting infrastructure) reports from the utility companies on how long they think it will take to, for example, repair the transmission lines. If you live in Portland, I implore you to sit down for an evening and take the time to digest this:
https://www.vice.com/en/article/8q8gyx/first-five-minutes-bi...
Don't panic, but take this seriously, this is a scientifically verified thing that will happen. It is never too early to consider things like earthquake retrofitting your home (bolting the frame to the foundation) and preparing emergency supplies like properly stored food and water. If you're on the coast, memorize your escape route, you won't have time to look it up and your phone won't work anyways.
It describes the anticipated impact of the impending megathrust earthquake by examining the first moments, hours, days, etc after the event.
This will be a huge disaster, but our government and institutions are not apathetic to it.
1. https://www.newyorker.com/tech/annals-of-technology/how-to-s...
2. https://www.seattle.gov/Documents/Departments/Emergency/Plan...
3. https://www.fema.gov/press-release/20210318/emergency-manage... (a 2022 exercise is planned)
Long ago a giant flood from the columbia river gorge filled a large basalt valley with hundreds of feet of clay silt. Today there are many hundreds of thousands of people living and working on top of the clay silt, including the entirety of Nike world headquarters and the majority of Intel's fabs.
When the earthquake hits, the entire basin is predicted to liquify, just like this:
Do you know how the early warning system works? How much advance warning do they expect to give?
All in all, the earthquake early warning system in North America still lies far behind to say the system in Japan.
It didn't happen all in one day, or year. But there were many places where the water moved inland by three feet per year; any beach one knew as a child was gone by adulthood.
Millions of square miles of what was lowland is now underwater -- the region between Indonesian islands; for hundreds of miles out to sea from Viet Nam all the way up to Korea; all the space between Australia and New Guinea; thousands of square miles off India; the whole Persian Gulf; England and Ireland were not islands; from Florida to Louisiana; from Argentina out to the Falklands.
These places were prime habitat (possibly excepting near the Falklands, and northern England), so not unpopulated.
It seems significant that the oldest known civilizations, in Mesopotamia and the Indus valley, arose immediately uphill from especially major inundations. Australian oral records have precise accounts of conflict resolutions over people moving uphill into land already occupied for 40,000+ years.
> This sounds like an eye-witness account of such an eruption, and it undoubtedly is, for Indian artifacts have been found buried in the Mazama ash. The eruption has been radiocarbon-dated to about 6500 years ago on the basis of Indian sandals found in the ash, but had no datable materials been found, this myth alone would have served to date the eruption as post-Pleistocene, because this part of the world was first inhabited by people who crossed the Bering Land Bridge and migrated down through Alaska and Canada into the northwestern United States.
Geomythology: geological origins of myths and legends https://sp.lyellcollection.org/content/specpubgsl/273/1/1.fu...
It sits on a 3500 diesel truck that can go just about anywhere.
I know this solution is not practical for everyone. But it is always fully fueled, fully stocked and offers considerable peace of mind. If you have been on the fence about buying an RV, think of it from this angle.
Complete devastation just isn’t my thing.
But yes. There's some balancing of unlikely but major natural disasters and fairly routine bad weather events.
From a natural disaster perspective you're probably best off in the desert Southwest.
If covid had gotten India/Italy bad, our plan was to evacuate to Hawaii or Mexico.
*not including extra packaged water, boats can hold quite a bit
1. https://en.wikipedia.org/wiki/1960_Valdivia_earthquake
2. https://en.wikipedia.org/wiki/1964_Alaska_earthquake
3. https://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake_a...
Those 3 amount for over 50% of all the energy released by earthquakes in that period.
https://upload.wikimedia.org/wikipedia/commons/7/79/Graph_of...
There's this one too: https://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_an...
The Bachelet administration was hesitant to mobilize the army due to the potential political cost (i.e.: bringing back memories of the Pinochet regime), so they took several days to make that decision and in the meantime things went completely out of control.
The same administration was also hesitant to evacuate the residents in the Juan Fernandez Islands, effectively causing many of them to die when the tsunami wave hit.
https://www.youtube.com/playlist?list=PLpwTojTevrmOfXmPVpGSa...
Edit: I'm nowhere near the area (I'm in Scotland) but I find the series absolutely fascinating.
For example, Did you know there's a connection between Yellowstone, Smith Rock in Oregon, and Liberty Gold in central Washington?
The possible connections between columbia river basalt and yellowstone is also very interesting.
It's just a fantastic place to be for geology.
Or you could build a larger number of small reinforced shelters that would be designed to be overrun but would keep people alive until the tsunami retreats.
https://pnsn.org/tremor?starttime=2021-04-01T00:00:00&endtim...
The projections of a moderate eruption of Mount Rainier (aka Tahoma/Tacoma) include flows reaching all the way to Renton/South Seattle.
The biggest risk from Rainier currently is lahars, aka mudflows. You don't need an eruption for those. The last big one was Kautz Creek in 1947. If you live in one of the valleys around Rainier there's a reasonable chance of seeing a lahar in your lifetime. (Hopefully from somewhere out of harm's way.)
Timeline: https://projects.oregonlive.com/maps/earthquakes/timeline
Ouch.
Most of the infill west of I5 in the Seattle area will probably liquefy, but there's mountain ranges to the west of I5 that would take a hell of a quake to toast.
Specifically, the perpetual habitability for humans
The quake itself and tsunami risk is the dangerous part for most people.
Nonetheless, id still be worried about things that will kill me, even if its not in the next 10 seconds. Dead is still dead.
There's no natural gas service anywhere else on the WA pacific coast, nor the northern coast of the olympic peninsula (Sequim, Port Angeles), or the west bank of the Hood canal. The entire Olympic Peninsula is without natural gas except for one metro area. They actually have to haul tanks full of the stuff to the paper mill in Port Townsend to use.
The aftermath will suck, however.
Are you saying that ""Our operating assumption is that everything west of Interstate 5 will be toast" has scientific value?
Are you saying that because of someone's tittle they are incapable of saying something hyperbolic?
Do you disagree with my word use? What is a better word?
I don't know if the statement is backed up by science, but its a falsifiable empirical prediction. It is entirely within the realm of science to make predictions that certain geographic regions will have significant structural and human damage in the event of some hypothetical natural disaster.
I agree. But that's not the same as saying it's "toast".
Maybe you think its inappropriately informal, but that is a stylistic concern, not a science concern.
That's debatable. It can mean anything from doomed to in trouble.
IDIOMS FOR TOAST be toast, Slang. to be doomed, ruined, or in trouble:
>Would you object if he said "utterly destroyed" instead?
Yes I would object.
Does it mean everything west of I5 is going to fall into the ocean? All human structures are going to be levelled? Only structures over 2 stories not made out of wood will be levelled? Or just that everything west of I5 will have more damage than everything east.
And I doubt that EVERYTHING east of I5 is going to share the same fate. The I5 is a human made road, not a geographic feature. It doesn't control earthquake outcomes.
If we're talking about Oregon it gets even weirder since the population centers have a coastal range in between them and seawater. I don't know enough about the various fields involved to know if the Columbia river's level would raise catastrophically in such a scenario.
You sure about that? From Olympia to the Oregon border I-5 sits on the lowest, flattest stretch of land between the coastal range and the cascades. That's why it keeps getting flooded out by the Chehailis river.
To the north, through Whatcom County the route is anything but geologically arbitrary: it's the unique route that required the minimum amount of blasting into Chuckanut rock.
Parent post seems like a pretty city-centric view of the world. The dozen or so miles that pass through Seattle might be arbitrary to within a Seattle-diameter, but that's an irrelevantly small part of the freeway.
The real risk is civil engineering in nature. While the fault is some distance away, it will shake hard and for a long time. Unreinforced masonry will probably be destroyed, and Seattle has a lot of old masonry in some neighborhoods. Some older structures not up to the current seismic code will likely fare poorly. Seattle has had enough local 7+ earthquakes that a distant offshore 8-9 won’t feel too much different, but the shaking time will be much longer. Landslides are undoubtedly a risk.
Portland will likely fare much worse than Seattle. A modern steel or wood-framed building constructed in the last 20 years will very likely survive almost anything, they are built for it. Older steel and wood buildings that are still standing have already been through some earthquakes; not as large but they won’t immediately collapse.
The real problem will be restoring infrastructure in the aftermath.
> Perhaps no line in the entire six-thousand-word piece attracted as much attention as this declaration by Kenneth Murphy, head of the fema division responsible for Cascadia: “Our operating assumption is that everything west of Interstate 5 will be toast.” The first important thing to note about that remark is that, needless to say, Murphy really said it, and stood by it in the fact-checking process—so, clearly, fema is anticipating that the region will be in very grave shape.
> That said, “toast” is not what you would call a precise description, so let me be more specific. What Murphy did not mean is that everyone west of I-5 will be injured or killed; fema’s casualty figures, while horrifying, amount to under one-half of one per cent of the population of the region. Nor did he mean that every structure west of the interstate will fail
I read that as, "we can use I-5 as a distribution backbone if we prioritize its repair because it is very unlikely to suffer too much damage." I also assume that simulations indicate it will not need much repair. Bonus points if we've already re-engineered the sections of I-5 most likely to need repair. It could save time later.
So now we can make a plan around what we're likely to have, and if we have more when the time comes it's gravy.
Basically, don't position all your recovery assets and facilities along the 101. Doesn't mean the 101 won't be there, it only means your plan has a smaller chance of falling apart if you position the facilities you'll need along I-5.
On the other hand...If somebody like Brian Atwater said it, that would really get my attention. He's one of the main geologists who tracked down the geological evidence to date the 1700 Earthquake. The force is strong in that one. [1]