When the Big One hits the U.S.

July 20, 2015 • 11:00 am

Professor Ceiling Cat has an article that he highly recommends you read. It’s in the latest New Yorker, and is called “The really big one” by Kathryn Schulz (subtitle: “An earthquake will destroy a sizable portion of the coastal Northwest. The question is when.”). It’s a superbly researched and written account (also free to access) of what’s going to happen when the Big Earthquake hits not California, but the Pacific Northwest.  The scenario is not pretty, with at least 30,000 deaths and massive destruction of the infrastructure. Here’s a short excerpt:

When the next very big earthquake hits, the northwest edge of the continent, from California to Canada and the continental shelf to the Cascades, will drop by as much as six feet and rebound thirty to a hundred feet to the west—losing, within minutes, all the elevation and compression it has gained over centuries. Some of that shift will take place beneath the ocean, displacing a colossal quantity of seawater. (Watch what your fingertips do when you flatten your hand.) The water will surge upward into a huge hill, then promptly collapse. One side will rush west, toward Japan. The other side will rush east, in a seven-hundred-mile liquid wall that will reach the Northwest coast, on average, fifteen minutes after the earthquake begins. By the time the shaking has ceased and the tsunami has receded, the region will be unrecognizable. Kenneth Murphy, who directs FEMA’s Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, says, “Our operating assumption is that everything west of Interstate 5 will be toast.”

In the Pacific Northwest, everything west of Interstate 5 covers some hundred and forty thousand square miles, including Seattle, Tacoma, Portland, Eugene, Salem (the capital city of Oregon), Olympia (the capital of Washington), and some seven million people. When the next full-margin rupture happens, that region will suffer the worst natural disaster in the history of North America. Roughly three thousand people died in San Francisco’s 1906 earthquake. Almost two thousand died in Hurricane Katrina. Almost three hundred died in Hurricane Sandy. FEMA projects that nearly thirteen thousand people will die in the Cascadia earthquake and tsunami. Another twenty-seven thousand will be injured, and the agency expects that it will need to provide shelter for a million displaced people, and food and water for another two and a half million. “This is one time that I’m hoping all the science is wrong, and it won’t happen for another thousand years,” Murphy says

In fact, the science is robust, and one of the chief scientists behind it is Chris Goldfinger. Thanks to work done by him and his colleagues, we now know that the odds of the big Cascadia earthquake [magnitude 8.0-8.6] happening in the next fifty years are roughly one in three. The odds of the very big one [magnitude 8.7-9.2]  are roughly one in ten.

. . . Together, the sloshing, sliding, and shaking will trigger fires, flooding, pipe failures, dam breaches, and hazardous-material spills. Any one of these second-order disasters could swamp the original earthquake in terms of cost, damage, or casualties—and one of them definitely will. Four to six minutes after the dogs start barking, the shaking will subside. For another few minutes, the region, upended, will continue to fall apart on its own. Then the wave will arrive, and the real destruction will begin.

Don’t miss this article. If you live west of Interstate 5, you may want to move, as the quake is way overdue.

h/t: Diane G.

76 thoughts on “When the Big One hits the U.S.

    1. The worst aspect of Rainier “popping off” wouldn’t necessarily be the ash, or even pyroclastic flows: it would the the lahars (mudflows) generated by the rapid melting of the mountain’s snowpack; one completely wiped out a town of 25,000 people in South America some years back. Core samples have revealed that most of the communities around Rainier sit on the tracks of ancient lahars (of course, like floodplains, they’re nice level areas in the midst of the mountains; easy to build on)- one particularly big one even reached the sea!. Major landslides are a distinct and looming possibility, too, as Rainier’s rotten rock slopes are nearly exceeding their maximum “angle of repose”- these slides have been known to go for miles, riding on a cushion of compressed air and rock dust.

  1. I recall the big one in Alaska, I think that was 1964? Anyway, there had to be some benefit to living in Iowa.

    1. Strictly, it’s not inevitable that the Cascadia subduction zone will go in a “big one”. But it’s far more likely to go that way than to dissipate it’s accumulated strain in a series of extended silent slip events.
      You might catch me there for a flying visit. Possibly even a sleep over. But I’d sleep with one eye open.

  2. I happen to be spending the month here at ground zero. It adds a little exciting edge to the place.
    Ha! Auto-correct tried to replace “place” with “plate”.

  3. I grew up in Tacoma and spent hours and hours sitting on the old Narrows bridge that spans a mile of Puget Sound from Tacoma to the Olympic Peninsula. Every time I sat there I thought the coming nine-point-oh. It won’t be pretty. Most devastating would be pyro clastic flows which could flatten and char everything in its path all the way down through river valleys from Tacoma to Seattle.

    1. … because the last time it “went” the only people around to notice didn’t have either writing or white skins.
      The Japanese did notice though, being somewhat puzzled by the tsunami “orphaned” from it’s predecessor earthquake.

      1. The folks who lived up a ways in BC tell the story of when the ground burned and that sort of thing. There’s a wonderful lava flow I remember visiting as a kid. It was possible to date the eruption to within a few days by taking the time mentioned in the story (e.g., approximately how many generations ago) then calculating that there would have been a tsunami hit Japan within a certain time (based on knowledge of such speeds, etc.). Then one can consult the written records there to confirm date; and then work backwards again for the events in BC. A wonderful combination of disciplines to solve this little puzzle – and the 300-400 year old rocks (I forget the precise dating) are quite remarkable.

        1. The folks who lived up a ways in BC tell the story of when the ground burned and that sort of thing. There’s a wonderful lava flow I remember visiting as a kid.

          “burned”, “lava flow” ? Associated with an earthquake. I think there is a caballus-carruca temporal inversion here.

            1. Earthquakes and volcanism are closely associated, but mostly the earthquakes are clearly consequences of the volcanism, not the other way around. With the exception of some “mud volcanoes” and some arguable cases in the Andes, there aren’t any clear cases of a volcano being triggered into eruption by an earthquake. OTOH, when up Mt Etna last week (which has been in a continuous state of eruption for centuries if not millenia), I was using earthquake records as an indicator of what was grumbling in the bowels of the volcano, and might be spitting out of the top when we got there.

      1. Good stuff. I really dislike the New Yorker article. It makes mush out of the known statistics for the purpose of generating interest.

        “In fact, the science is robust, and one of the chief scientists behind it is Chris Goldfinger. Thanks to work done by him and his colleagues, we now know that the odds of the big Cascadia earthquake [magnitude 8.0-8.6] happening in the next fifty years are roughly one in three. The odds of the very big one [magnitude 8.7-9.2] are roughly one in ten.”

        Well, no, not at all. These odds are based off one particular model built upon several nested assumptions, and is only one of several that the authors talk about in the sourced report. See: http://goo.gl/8mScho

        There is a TON of information in that report, and a lot of really great science. But what everyone is focusing in on of course are the various projections of the models near the end of the document (I have not read the entire thing, only parts). There are two items that I’ll draw attention to:

        1. The periodicity of Cascadia earthquakes is unknown. Pages 119-122 of the report discuss this in some detail. The number of events the authors have to address the question of periodicity is very small (19 events), so they have virtually no power to detect periodicity with any precision. This is evidenced by the fact that the data “fit” a dozen different distributions equally well. The upshot is that there is no way to tell if the intervals between events are normally distributed, or if the distribution has a much heavier tail (i.e. intervals between events are commonly much longer and more variable). Previous work and theoretical knowledge suggest that these events are heavy tailed. All this means that we have little to no evidence that large earthquakes in the Cascadia region occur with any reasonable regularity. So we can’t say that we’re getting overdue.

        2. I’m not quite sure where the New Yorker pulled out those odds. Notice that they don’t provide any measure of uncertainty attached to the estimates. All I have been able to find so far in the sourced report that comes close to that is, “Failure analysis indicates that, by the year 2060, ~85 percent
        of recurrence intervals will have been exceeded along the southern
        margin.” This is one estimate of three that the authors discuss, and it is restricted to the southern segment of the Cascadia region (northern California). The other, more “catastrophic” numbers are far less scary than what the New Yorker reports (see pages 136-138 of the Goldfinger, et. al report).

        1. First thank you for the link to the original USGS report. Spent the afternoon reading the report, scrutinizing the numerous graphs and charts, and as you stated ‘there is a ton information’. I, like you, do not fully embrace the New Yorker article. However, the original report was of sufficient depth with sound analysis to convince me not to retire to the Northwest nor hold shares long term in Boeing stock despite the incredible performance of the last 10 years. The report was indeed filled with great science and not politically laced as reports focused on the earthquakes swarms inflicting Oklahoma and the Midwest. The bottom-line is we need solid science investigation and truly embrace risk as a society and as individuals based upon science.

          1. Glad you found the report useful. I live in the Pacific NW and don’t plan on leaving anytime soon. But the report certainly highlights the need for cities to be ready for the worst. Here in Vancouver, BC, we still don’t have many buildings up to earthquake-sound structural code (many public schools!). As with Seattle, Vancouver would be pretty protected by its geography from any major earthquake off the coast, but there are plenty of fault lines lying around. A bit more preventative infrastructure would be a very good thing.

  4. If you live west of Interstate 5, you may want to move, as the quake is way overdue.

    Of course if you move east, the Yellowstone supervolcano (also overdue to erupt) could get you.

    There’s probably not a place on earth that is (1) pleasantly habitable and (2) stable over a time period of the next ten thousand or so years.

      1. That’s where I am going. In any event, natural disasters do tend to bring people together, so it’s not all bad.

      2. Hawaii (or at least the eastern facing parts of it) would be taken out by the same earthquake/tsunami combo that would take out the cascade region.

        1. Hawaii would be hit by the same tsunami wave, but since Hawaii is about 2000 miles from the subduction zone as opposed to 50 to 300 miles for Pacific Northwest coast, the tsunami wave will dissipate and will be several times smaller than the one that hits Oregon. Another advantage of being in Hawaii – due to the islands being farther away, the wave would hit Hawaii more than an hour (or even a couple of hours) after the earthquake which would give much more time to evacuate.

          1. Evacuate yes. That is a nice way to put it. I lived on Oahu, I assume that is where you mean, for 5 years. One time, in the middle of the day they blew the sirens due to an earthquake up near Alaska and expected a tsunami. They let everyone off work about 2 pm so everyone got in their cars to go home or wherever. It was one giant car park for hours. We sat in cars on the Pali highway until 8 pm. I don’t think there is any evacuation of that Island unless you are already at the airport and maybe on the plane.

        2. Or the next sector collapse.
          Lituya Bay produced a wave of nearly a thousand feet. A good sector collapse could beat that. And oceanic volcanic islands are almost sculpted by sector collapses – I was looking at one in the flanks of Etna just 4 days ago.

    1. I live in Australia, the most stable continent in the world. We rarely have any earthquakes, there are no volcanos. Apart from the threat of rising sea levels, huge sharks, funnel web spiders, crocodiles, drop bears and flies the size of wood ducks it is nice and safe here.

    2. As Stuart says, Australia is the safest place on the planet to live, geologically and politically. The wildlife is pretty deadly but most of us never go anywhere near it, if the truth be told.

      1. Only those of us who like to. It’s optional. Mostly.
        Actually I can’t concur on ‘safer… politically’. Sure it’s a democracy and has social services (for now), but somehow managed to elect Tony Abbott, one of democracy’s more shameful moments since 1933.

    3. That’s pretty much my thinking as well.
      As I read the New yorker article yesterday, I kept thinking about the likelihood of being struck by a Tornado, or a Cat 5 hurricane that shifts direction suddenly, putting evacuees directly in its path. Not as devastating as “the Big One” per se, but your point that nowhere is totally immune from natural disaster stands.
      The more information and critiques of the New Yorker article I read, the more I am disappointed in its click-bait alarmism.

  5. Colleagues mentioned this article (or was there also something on TV about it recently?) as well … I’ll try and read it tonight. For now I am wondering, does the article mention what the tsunami will do to Japan?

    The 15 minute warning between quake occurring and the tsunami arriving on the west coast is just … nothing at all, really.

    1. I don’t think it does but the history of the discovery of Cascadia subduction megaquakes was aided by Japanese historical documents describing an aberrant giant tsunami (no preceding quake) in a year consistent with what the coastal sediments in Washington suggested as the timeline for the last big one.

    2. FEMA projects that nearly thirteen thousand people will die in the Cascadia earthquake and tsunami.

      The 15 minute warning between quake occurring and the tsunami arriving on the west coast is just … nothing at all, really.

      If you recognise the event for what it is, it’s a 15 minute head start to get up the nearest hill, or really, really solid building.
      For another decade or so, we can reasonably hope that many people will remember the Boxing Day tsunami. Then they’ll forget.

  6. Not that I wish for more, but I’m surprised by the prediction of such a relatively small number of deaths. The article states that 7 million people live in the region but predicts 13,000 dead and 27,000 injured. I sincerely hope that’s correct. If a city the size of Seattle is deluged by a wall of water taller than the people, it seems like many more deaths and injuries are possible. Fortunately, I have no science or statistics to back up my fear.

    1. Seattle is about 80 miles from the open ocean, with a range of mountains in between, and is in no direct danger from a Pacific Coast tsunami. The New Yorker article is very misleading in that respect.

    2. Given that the US has a generally well-fed populace, and has for a long time (a generation of buildings) had reasonably good building codes, reasonably strongly enforced, and the in-country resources of both money and materials to mobilise aid internally and rapidly, such a low death toll doesn’t particularly surprise me.
      for a long time, I’ve been laying my bets for the first mega-death earthquake for the Ganges plain. The recent slight tremblor in Nepal hasn’t done anything significant to decrease the accumulated strain there.

  7. What impresses me is that when the 2011 earthquake shocks reached Tokyo, the buildings withstood them, there were almost no casualties, the water, gas, and power systems did not fail (the exception being the Fukushima power station which was much closer to the epicenter). So with diligent application of earthquake codes, it is possible to reduce the disastrous effects.

    For a tsunami to reach Seattle it has to go the length of the Strait of Juan de Fuca, turn the corner, go south about 60 miles to Seattle. Then to totally submerge the city it has to overtop some hills that get up to 400 feet in height.

    Of course the effects of a magnitude 9 earthquake in the subduction zone would be very extreme, but the article makes it sound as if Seattle was built on flat land next to the ocean.

  8. Judging from the few gluten-free bakery products I’ve consumed (by accident or out of hungry desperation), I think they could be used to block the lahar from Mt. Rainier and to lessen the destructive force of the tsunami. If there were more such bakeries here in Texas, I’d be testing their “breads” and “cupcakes” to prevent erosion on Galveston Island.

    Get to work, Pacific NW gluten-free bakeries!

  9. What is remarkable about the story of the Cascadia subduction zone is that it was built upon inferential science–predicting likely future events based on long-past historical events. Exactly the same kind of science that underlies much of our knowledge about anthropogenic climate change. I wonder if there will be a move on the right wing to deny the risk, or even more absurdly, to deny that the subduction zone even exists. You know, the whole, “were you there?” riposte to the reconstruction of an earthquake that took place in 1700. That might sound glib, but incorporating the necessary protective measures would be hugely expensive (though far less so than the recovery). It kind of screams “job killer”. The right probably already views the New Yorker as a liberal rag, and we already know how they feel about all those egghead scientists who try to learn stuff. So I can see the same kind of motivation for denial and willful ignorance as exists for climate change. It is perhaps only a matter of time before Kathryn Schulz becomes linked to Al Gore. Stay tuned.

    1. It kind of screams “job killer”.

      Not to me. Seismic retrofits and other infrastructure upgrades seem like an excellent way to create jobs that can’t be exported overseas.

      1. What I mean by that is it screams “job killer” in the same way that CO2 mitigation does; which is to say not at all to rational people, but only to people who view any increase in government expenditure as a job killer.

      2. True, but the right-wing in America is staunchly opposed to infrastructure spending.
        They only talk about job creation because it plays on the campaign trail. In reality, they’re all in favor of exporting jobs.
        Gotta get at that cheap foreign labor because patriotism means making American workers compete on the labor market with sweatshops.

  10. The article had me seriously rethinking a vacation to the Pacific Northwest. I wish it didn’t, but it did.

  11. I do very much appreciate Ms. Schulz got it right that it’s the upper plate rebounding, not the lower plate becoming unstuck. Dawkins in the Magic of Reality really got my teeth grinding when he said, the plates are moving in jerks.

  12. About 20 years ago I was asked to develop a disaster plan for a health system in Oregon. Silly me, I took the exercise seriously. I will never forget the looks on the faces of the assembled admin people when we reviewed the section on what I called, “Unactionable megadisasters” These were scenarios where there really was no reason to develop an action plan because all of the Emergency infrastructure was going to be destroyed. Some of the city planners liked one idea for installing seismically reinforced landing pads strategically in the medians of the various interstates and major highways to create an LZ grid within the city to support emergency airlift. The space was there and there were no overheads to endanger rotorcraft approaches and landings. Plus, there wouldn’t be any rubble to fall onto the pads. The idea was to simply include these as part of new build roads or during repaving. No money was ever allocated for it.

  13. I could be wrong, but it’s my understanding that Vancouver’s buildings are not so earthquake ready. Of course, that doesn’t matter if you’re wiped out by a tsunami.

  14. The description of what can happen is nothing new though; Chile was whacked by a 9.5 quake back in 1960; it was a peculiar event since the shocks traveled around the world several times – it’s extremely rare that you can look at seismograms over about 2 days and see the same shock pattern appear multiple times. Chile was whacked by another (close to Mag. 9 I think) only a few years ago. Anyway, with several monstrous earthquakes in relatively recent history it’s not at all difficult to imagine what can happen. As for the guess at the likelihood (1 in 3 for >M8 in 50y) I don’t believe that at all. There are no established patterns for earthquakes at plate boundaries and averages of past events tells you nothing of the likelihood of a future event. If you had a reliable model for measuring how much stress is building up and when something might fail that would be a start. I imagine it would be quite a challenge for such a model to work on a large scale; it’s tricky enough to do for the small local faults that the oil and gas industry deal with on a daily basis.

    1. And in particular Darwin’s observation:

      Captain Fitz Roy founds beds of putrid mussel-shells _still adhering to the rocks_, ten feet above high-water mark: the inhabitants had formerly dived at lower-water spring-tides for these shells. The elevation of this province is particularly interesting, from its having been the theatre of several other violent earthquakes, and from the vast numbers of sea-shells scattered over the land, up to a height of certainly 600, and I believe, of 1000 feet. At Valparaiso, as I have remarked, similar shells are found at the height of 1300 feet: it is hardly possible to doubt that this great elevation has been effected by successive small uprisings, such as that which accompanied or caused the earthquake of this year, and likewise by an insensibly slow rise, which is certainly in progress on some parts of this coast.

  15. It will happen someday, nobody knows when.
    Hopefully not while I’m here.
    It makes us people look kinda small, eh?

    1. But you will have the coming apocalypse, with the marauding motorcycle gangs terrorizing the survivors, and nothing but a sullen loner and a gyrocaptain to help you.

  16. 10+ miles east of I-5 and 35 miles north of Seattle. I think we’ll be safe. Just hope I’m not visiting Seattle that day.

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