Have we discussed the Cascadia subduction zone yet?
 

This one looks a lot more likely to happen in our lifetimes than the Yellowstone caldera blowing. I had never heard of this. Very bad news and a matter of when, not if. Must read.

The Earthquake That Will Devastate Seattle - The New Yorker

I just read that 5 minutes ago. Considering how I may not survive it, sort of a big deal.

I've known about it for a long time. (I'm a geologist) But it's true, its seems to be known by very few people, even among those that are in danger. It won't be pretty.

Article is very viral in my neck of the woods (Seattle). I live way up a hill, but work downtown where things could get really ugly with soil liquefaction and a half cocked tunnel project running under my building.

Wow. Not good at all. Why isn't more being done in the PNW to prepare for something like this?

Your not California that has had big movements before which have wrecked havoc...

Cajon 1859, Sand Francisco 1906, Long Beach 1933, Silmar 1971, S F again late 80's, Northridge early 1992, Then Landers and Big Bear mid 90's. SmileWavy

Makes me glad to be in South Georgia far from techtonic plate edges, volcanoes, tsunamis, etc.! All we have to worry about are hurricanes, tornadoes, snakes, rabid wildlife and drunk rednecks!

Getting anything at all done in Seattle is next to impossible, between getting people to vote for it, environmental studies, legal challenges from people affected and The Sierra Club... It's a miracle that anything at all can be accomplished.

I used to live in Lower Queen Anne and took the Viaduct to get to work at BFI. When traffic would stop completely I could feel the traffic on the upper level gently shaking the roadway, and I'd often times think about how it would be a really bad time for even a medium sized earthquake to hit. It was right around the time that WS DOT made that video that showed the Viaduct collapsing, sections of Alaskan Way sliding into the harbor, fires starting and things like that.

I thought a good chunk of downtown, basically from the Sound to 2nd Ave was more or less built on fill and the area used to be a marsh?

Thanks for posting that. I enjoyed the writers style and how the information was presented.

I had no idea that the earthquake in Kashiwa lasted over three minutes.

Very interesting article. Even those of us in flyover country aren't immune to earthquakes. The New Madrid fault line (abut 150 miles southeast of where I live) has the same potential for devastation as Cascadia and has demonstrated its power in the past:

1811–12 earthquake series[edit]

Main article: 1811–12 New Madrid earthquakes
December 16, 1811, 0815 UTC (2:15 a.m.); (M ~7.2 – 8.2[9]) epicenter in northeast Arkansas; it caused only slight damage to man-made structures, mainly because of the sparse population in the epicentral area. The future location of Memphis, Tennessee was shaken at Mercalli level nine intensity. A seismic seiche propagated upriver and Little Prairie was destroyed by liquefaction.[10] Local uplifts of the ground and water waves moving upstream gave the illusion that the river was flowing backwards.[9]
At New Madrid, trees were knocked down and riverbanks collapsed. This event shook windows and furniture in Washington, D.C., rang bells in Richmond, Virginia, sloshed well water and shook houses in Charleston, South Carolina, and knocked plaster off of houses in Columbia, South Carolina. In Jefferson, Indiana, furniture moved and in Lebanon, Ohio, residents fled their homes. Observers in Herculaneum, Missouri, called it "severe" and said it had a duration of 10–12 minutes.[11]Aftershocks were felt every six to ten minutes, a total of 27, in New Madrid until what was called the Daylight Shock, which was of the same intensity as the first. Many of these were also felt throughout the eastern US, though with less intensity than the initial earthquake.[11]

Great article, RL. Thanks for posting it.

It is well written. I wish I could write like that.

Thanks for posting that link.

Well, the media has spoken, This is old news to many of us I the NW. It falls under the category of "**** happens". (or is going to). At my age, I will prolly just have a heart attack during the event and miss the aftermath.
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Hoy cow. So much for high property values.

Here's hoping for the best for you guys. Despite our many issues here in jersey at least the ground doesn't move much at all.

Great read, RL. Thanks.

If that happens it will put quite a dent in the world's hipster population.

I finally plowed through the whole article.
The devastation potential is understated.

For instance, nearly all the Boeing production facilities are built on land fill or delta of various rivers in Seattle. First, liquefaction then flood. In a few hours, Boeing ceases to exist as a viable company.....not to mention, the loss of life ......Buy Airbus stock, eh?

During the last "big one" in Alaska, the tidal surge moving up fiords moved up to a height of 1200 feet when it reached the end of the channel. Those channels were small compared to Puget Sound. The nuke boats in Bremerton are in a similar fix.

I hope to be taking he dirt nap when this event takes place.

The brevity of our lives breeds a kind of temporal parochialism—an ignorance of or an indifference to those planetary gears which turn more slowly than our own.

I have kept tellin ya all for years about taking a longer view of the American economy....

Back when I was into predicting Earthquakes on this Board...I first got interested in it because of the Humboldt fault zone off of N California...it is one of the more active zones as it frequently ruptures with 5's and 6's. I was figuring that if something happened on this side of the Ring of Fire it would put pressure on the other side to eventually move as well. In sort of a seismic dance. I kind of gave up thinking about it as a fools errand because TABS time does not correspond to geologic time..

Then comes the money to rebuild the PNW if and when..with the US and worlds state of finances good luck with rebuilding.


Take a look at the time line...in 1964 Alaska suffers a 9.2 Quake along the Denali fault zone...the land pushes out or snaps back 66 feet to the south That has to put pressure on the Cascadia fault zone in a SE trending direction which in 1982 causes Mt St Helens to blow. There has been and is a lot of activity on the Humboldt fault in N CA which is where San Andreas and Cascadia meet. Now Cascadia has gone quiet, So where is Cascadia going to rupture...go due west of Mt St Helens.

What u have to remember is that the Tectonic plates are always readjusting themselves to relieve pressure that has built up. When you take a little pressure off here X, pressure begins to build over there > Y.

Now if I told you all the exact time, you all wouldn't remember so what is the use.

Yawn.

This is old and accepted news. In Washington alone we have three big a$$ volcanoes (OK, two and a half) and the entire Puget Sound is resplendent with fault lines. A lot of Seattle is built on fill (Downtown, Harbor Is, Greenlake) and effecting all this is the subduction zone. Anyone paying attention would be comfortable saying it is going to be catastrophic if something happens.

And just what can be done about it? Empty Downtown and rebuild on bedrock? Build a big dam around the Sound as a seawall to control the tsunami? Raise all the Boeing plants up on stilts? Maybe some causeways to control the flooding from Rainer or Baker blowing up? As mentioned by Scuba Steve, Seattle is not well know for progressive thinking about infrastructural improvements.

So, what should be done to better prepare for an earthquake, eruption or tsunami to protect millions of people over hundreds (thousands?) of miles of coastline?

Wow, that was a frightening education. Incredibly well written article. I think I'll keep our tornadoes.

The comparison to Japan is interesting as well. That country is obsessive about their tsunami warning systems and safety plans, yet thousands still died. Having a similar event in a populated region that has no warning and no plan is a frightening proposition.

The best thing would be to figure out a way to make millions of dollars off of it. I'd start with a PR campaign which includes a slick propaganda movie complete with Polar Bears and Hockey sticks.

PBS recently ran a program on mega-quakes & the Pacific ring of fire - nothing new by way of information but quite sobering with respect to the 'what if' factor.

Cheers
JB

I heard that each year there is a 1 in 300 chance of a big quake hitting the upper left coast - a disaster. While those odds are a bit high, it still seems better than living in a place that has an annual Disaster Season. YMMV;)

the fiords actually focus the tidal energy. So, I expect, places like La Conner will be La Goner, but Seattle proper (on a steep grade, and wide open water) will stay mostly in tact (from tsunami water)

You cannot prevent or survive such an event. You can only be somewhere else when it happens.
That works fine for people. Early warning systems and evacuation routes are about all you can do.
But if a huge Tsunami hits, who really gives a rip if the power grid is shut off in advance. Sure that might prevent a few fires. But it's not like the water is going to recede and I'm going to plug in my toaster and have a spot of tea.
So the time and expense to protect against the loss of infrastructure from such an event is a fools errand. Get the people out and rebuild. If the big one hits with any kind of force described in that article, no amount of planning is going to save the physical assets of the area. Focus on saving people and the only viable way to do that is to warn them and figure out the fastest way to get them the hell out of there.

If it happens in my lifetime, I'll definitely tune in and watch.

I'm buying land in western Idaho - new oceanfront property!

Did a master plan for Harborview Hospital some time ago. For those of you who have driven the 5 into Seattle it is the pile of bricks in the east side of the interstate on top of the hill just before you reach the first downtown exit. My structural engineer used the code madated ground movement to require horizontal movement of 5 or so feet and a vertical component of 3 feet or so. But he had studied the Cascadia science and basically said no structure in Seattle will survive the actual event. Harborview that is the trauma center for 5 states will end up on the 5 at the bottom of the hill. In his view vertical displacement of 30 to 100 feet can be expected. Frankly speaking the 1906 SF earthquake is a cakewalk in comparison. Even the New Madrid quake that re routed the Mississippi River is no match for the a Cascadia big one

I lived in SF for 10 years so I think I get the fatalism of living on the fault line. I did a project in Bellevue WA where the code officials were/are in denial about the need for seismic safety. Not much you can do if your choice is to live in the Pacific Northwest. Love the landscape and really like Seattle. Not a place I would want to be when this event happens.

Guess now we should move on to the Yellowstone super volcano

I've long been a student of plate tectonics, and believe this one is the next great 'natural' threat to the Continental US. I go riding up there 3 times a year. I always bring lots of extra food, and the first thing I do is fill the MH water tank. Cascadia is no joke. Especially since it's a subduction, which means when it goes there's a better than good chance Ranier will throw a few tissy fits. If you search the net, there's actually a picture of the fault line out in the Pacific, and you can see where it's turning down into the crust. I believe the Jaun de Fuca plate is the small one causing the confusion. Kind of like an island stuck out in the great sea. Lots of reading available on this.

300 MPH winds from a F5 hit a VERY small area and really mess that one tiny little area up. The vast majority of the city does not even have a blip on the electricity. Life goes on as normal.

With a 9.0+ earthquake and giant tsunami thousands of SQUARE MILES are devastated with no warning and no way to survive.

We have a tornado shelter. There is no such thing as a earthquake shelter or a tsunami shelter except to get the F**K out of the area. That will be impossible.

FWIW, they've had some 3 + 4 earthquakes up there the last few months. LOTS of small ones is a good thing. NO small ones,,,,bad. I have lived on and near faults my entire life, and been thru several. ^^^^^^^ Point well taken, but I'll stick with earthquakes over them 'nados any day.

Yellowstone Caldera, Global Warming, Cascadia Subluxations or whatever you call it, you choose your poison. I'm staying in Michigan. The biggest threat to our survival is Detroit.

You might have the biggest obstacle to overcome!!

A much shorter but older article.

13-Year Cascadia Study Complete — And Earthquake Risk Looms Large
Chris Goldfinger
August 30, 2012
https://ceoas.oregonstate.edu/features/pnwearthquakerisk/
http://forums.pelicanparts.com/uploa...1436904739.jpg

Have you noticed that everywhere you look, especially on television and the Internet, that the world is coming to an end very soon?

I remember thinking as an 11-year old kid in 1973 that there wouldn't be any gasoline when I was old enough to drive. Then there would be but the price would be too high. Then gasoline-powered cars would be done away with and we'd be in electric cars or riding bicycles. After almost 45 years of gloom-and-doom about oil supplies we are now in a global oil glut (for various reasons) and the price per barrel is just under 60 bucks today.

So now I'm supposed to get scared about a huge earthquake that no one actually knows when it's coming?

Oil is a supply and demand thing, totally unrelated to apocalyptic disasters. Oil could become far more scarce and still get cheaper due to lack of demand in the future. This Cascadia earthquake is pretty much a guarantee, just a matter of time, not world politics or economics. It could happen tomorrow or in 100 yrs., but it will happen. Seems to me it's even more of a sure thing than Yellowstone blowing up and that's pretty much a guarantee too; just with a much longer period between eruptions.

We're going to be hit by a massive meteorite again too. (shrug) Well, now that the whole "global Warming" thing fizzled ... we need something to fear.

interesting. Thing is, we don't know how the energy of slipping plates will be released. That is, massive energy can be sharp, or spread out. Shifting with a slow large displacements, and/or with small sharp waves. A mag 9.x relates to energy released; and those quakes are often many minutes long. (which spreads the energy over time) The distance away from the center is important too, as the energy falls off quickly. 1/R^2.

So, while it's fun to extrapolate the effects of a small close quake to that of a very large quake off the coast, it often doesn't work the way people would expect. (Hollywood style)

I expect that the damage to Seattle proper is WAY over stated. The coast will be hammered hard, Victoria will not be pretty and Whidbey island will become two islands.

Tornadoes impact neighborhoods. I will be safe in my basement. When this event occurs the human and economic impact will likely eclipse the sum total of every tornado in the USA.