The Really Big One – The New Yorker

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. […] 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.

In the Pacific Northwest, the area of impact will cover 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.

Kathryn Schulz won a Pulitzer Prize for this article in the New Yorker. The magazine highlighted this again on Facebook. I recall reading it the first time and wondering: has the tech industry in the United States developed contingency plans for an event like this? An earthquake of this type would decimate the industry, which is all concentrated in a small area.

… we now know that the Pacific Northwest has experienced forty-one subduction-zone earthquakes in the past ten thousand years. If you divide ten thousand by forty-one, you get two hundred and forty-three, which is Cascadia’s recurrence interval: the average amount of time that elapses between earthquakes. That timespan is dangerous both because it is too long – long enough for us to unwittingly build an entire civilization on top of our continent’s worst fault line – and because it is not long enough. Counting from the earthquake of 1700, we are now three hundred and fifteen years into a two-hundred-and-forty-three-year cycle.

This 243-year cycle is an average, of course, but still…

I hope we don’t see this in my lifetime, but if we do, it won’t be like in the movies.

Source: The Really Big One – The New Yorker

2 thoughts on “The Really Big One – The New Yorker

  1. Oh no, you pushed a button…

    It was a great article to get people in the pacific northwest doing something about being prepared–residential earthquake retrofit contractors are now backed up nearly a year, and a lot more people finally keep at least a few days of food and water ready to grab. It has some severe flaws though. A couple, such as saying that “everything west of I-5 will be toast”, instead of “right near the coast might be toast”, are partly rectified in the followup article, “How to Stay Safe When the Big One Comes”:

    http://www.newyorker.com/tech/elements/how-to-stay-safe-when-the-big-one-comes

    But Shultz also either completely misunderstands our geology, or else decided to vastly oversimplify it, which is Not Helpful. The potential quake hazards in Washington state are a good bit more, um, interesting. We not only get the subduction zone quakes (which Schutz covered) that will be bad but not catastrophic in Seattle, and deep quakes that are common around the Pacific rim but poorly understood; WA also has a large number of shallow and dangerous east-west running faults. The Seattle Fault that runs through south downtown was the first discovered and is the best known and studied, but the worst system is perhaps hundreds of miles long and has the potential to affect not only the Puget Sound area, but eastern WA–including the Hanford nuclear site–as well.

    The USGS shake maps for the Cascadia and Seattle faults are illuminating:

    http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/Casc9.0_expanded_se/download/intensity.jpg

    http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/SeattleM7.2_se/download/intensity.jpg

    There’s a nice simulation from the WA transportation department of what a large, but not enormous, quake could do to an elevated roadway and the seawall in downtown Seattle:

    “Full-rip 9.0” by Sandi Doughton is an excellent book and goes into things pretty thoroughly, including the detective work for how it’s been discovered. One spoiler: If the Cascadia subduction zone lets loose up here, savvy people in CA may want to get out of Dodge. Historically, parts of the San Andreas Fault often?/sometimes? lets loose a ‘few’ years later.

    Contingency plans for industry? That’s apparently each company’s problem. Emergency planning is improving at the local, and to a lesser extent, state levels, but there’s a long way to go. There’s certainly no money in the budgets to retrofit/repair older public buildings and bridges to current code at a reasonable rate. A lot of our schools are still in the queue, and WA has at least 145 bridges that will probably collapse.

    And all of this doesn’t even mention our volcanoes! Definitely an interesting place to live. Tip: Don’tt buy a house in the Kent Valley…it’s nice and flat because of all of the lahars that have flowed through it.

  2. Oh no, you pushed a button…

    It was a great article to get people in the pacific northwest doing something about being prepared–residential earthquake retrofit contractors are now backed up nearly a year, and a lot more people finally keep at least a few days of food and water ready to grab. It has some severe flaws though. A couple, such as saying that “everything west of I-5 will be toast”, instead of “right near the coast might be toast”, are partly rectified in the followup article, “How to Stay Safe When the Big One Comes”:

    http://www.newyorker.com/tech/elements/how-to-stay-safe-when-the-big-one-comes

    But Shultz also either completely misunderstands our geology, or else decided to vastly oversimplify it, which is Not Helpful. The potential quake hazards in Washington state are a good bit more, um, interesting. We not only get the subduction zone quakes (which Schutz covered) that will be bad but not catastrophic in Seattle, and deep quakes that are common around the Pacific rim but poorly understood; WA also has a large number of shallow and dangerous east-west running faults. The Seattle Fault that runs through south downtown was the first discovered and is the best known and studied, but the worst system is perhaps hundreds of miles long and has the potential to affect not only the Puget Sound area, but eastern WA–including the Hanford nuclear site–as well.

    The USGS shake maps for the Cascadia and Seattle faults are illuminating:

    http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/Casc9.0_expanded_se/download/intensity.jpg

    http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/SeattleM7.2_se/download/intensity.jpg

    There’s a nice simulation from the WA transportation department of what a large, but not enormous, quake could do to an elevated roadway and the seawall in downtown Seattle:

    “Full-rip 9.0” by Sandi Doughton is an excellent book and goes into things pretty thoroughly, including the detective work for how it’s been discovered. One spoiler: If the Cascadia subduction zone lets loose up here, savvy people in CA may want to get out of Dodge. Historically, parts of the San Andreas Fault often?/sometimes? lets loose a ‘few’ years later.

    Contingency plans for industry? That’s apparently each company’s problem. Emergency planning is improving at the local, and to a lesser extent, state levels, but there’s a long way to go. There’s certainly no money in the budgets to retrofit/repair older public buildings and bridges to current code at a reasonable rate. A lot of our schools are still in the queue, and WA has at least 145 bridges that will probably collapse.

    And all of this doesn’t even mention our volcanoes! Definitely an interesting place to live. Tip: Don’tt buy a house in the Kent Valley…it’s nice and flat because of all of the lahars that have flowed through it.

Leave a Reply to gastropod Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.