Future toast


This has me wondering if it would really be that bad to live in Oklahoma, or maybe Kansas – this article in the New Yorker about the fact that when the Cascadia subduction zone finally snaps, the resulting tsunami will wipe out everything west of the I-5 freeway that runs from southern California to the Canadian border at Blaine, Washington. I live a couple of miles west of I-5. The article is titled The Earthquake That Will Devastate Seattle.

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.”

But wait a second. There’s a mountain range between Seattle and the ocean. I’m looking at it right now – the middle of it is due west of me.

So I guess Seattle will just be shaken and smashed like the rest of the region.

 

Comments

  1. Pliny the in Between says

    Volcanoes, earthquakes, and tsunamis are the price those of us lucky enough to wake up surrounded by the incredible beauty of the Pacific Northwest are stuck with. 😉

  2. anthrosciguy says

    Have these folks not looked at a map? There’s a lot of territory, and mountains, between I-5 and the coast.

  3. Trebuchet says

    I’m no expert, but we do have the Strait of Juan de Fuca acting as a big funnel into Puget Sound. Puget Sound tides are higher than on the coast, IIRC. It might take the tsunami a while to get down the Strait to Seattle, but the wave could be growing taller all the time. I need to do some research. Or ask Dana Hunter.

  4. says

    I’m no expert either, but it seems reasonable to think that a huge section of the tsunami would break against the mountains (or their foothills) rather than Seattle, and that the northerly section funneled in by the Strait would break against the San Juans and Whidbey and other odds and ends before making it to Seattle.

    But probably what the geologist was saying was that the shaking and liquifaction would make the western half of Seattle toast, rather than the tsunami. The headline is perhaps confusing, as headlines so often are.

  5. embraceyourinnercrone says

    This is from the magazine Outside, from a few years ago, written by a coastal hazards specialist with Ocean Sea grant/OSU

    http://www.outsideonline.com/1819046/totally-psyched-full-rip-nine
    Full Rip 9

    And granted this could happen a few years from now or 600 years from now, but it sounds terrifying.

    The biggest quake I’ve been in was Northridge which was about 6.7 for less than 30 seconds. That was bad enough. Supposedly the Alaska Good Friday earthquake in 1964 was 9.2 , for 4 minutes…..NO Thank you

    I would like to live someplace with no natural disasters please! Yeah I know, not happening…

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