Would not be complete without this fantastic article: https://www.newyorker.com/magazine/2015/07/20/the-really-big...
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
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:
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.
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.
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 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...
https://www.oregonlive.com/today/2016/04/really_big_one_puli...
That's the next earthquake.
https://pnsn.org/blog/2020/01/27/getting-ready-for-the-next-...