> Take your hands and hold them palms down, middle fingertips touching. Your right hand represents the North American tectonic plate, which bears on its back, among other things, our entire continent, from One World Trade Center to the Space Needle, in Seattle. Your left hand represents an oceanic plate called Juan de Fuca, ninety thousand square miles in size. The place where they meet is the Cascadia subduction zone. Now slide your left hand under your right one. That is what the Juan de Fuca plate is doing: slipping steadily beneath North America. When you try it, your right hand will slide up your left arm, as if you were pushing up your sleeve. That is what North America is not doing. It is stuck, wedged tight against the surface of the other plate.
Here's a great video by Nick Zentner, who teaches at Central Washington University, on that article and has a lot of updated info and debunks some claims made.
What kills me is the often repeated claim that some massive tsunami is going to wipe out everything up to I-5 (about 60-80 miles inland in Oregon).
Most of the analysis I've seen seems to completely ignore the existence of the Oregon coastal mountain range, a 4000 ft high mountain range a few miles inland along the entire Oregon coast (basically Astoria to Florence).
Even in the worst case scenario, maybe some coastal towns are going to have a bad day, though they are all very well outfitted with tsunami alarms and maps that basically say to go a mile or so inland, so I doubt there would even be any significant loss of life.
A large enough tsunami could travel up the Columbia a significant distance. Even a town like Rainier could be at risk though Portland should be fine.
I think the "everything west of I-5 will be toast" refers more to Seattle, where all of downtown is built on fill pulled from the Sound 100+ years ago. For everyone else, the biggest risk is being completely cut off when all of the bridges fail.
Are the claims made by the professor still accurate given that the video is seven years old and we have been hearing for years that our infrastructure hasn’t been doing so well? I guess it might not be “toast”, but I can’t imagine having to wait weeks to get emergency aid and resources.
Paleoseismology is a pretty fascinating area of study that involves Japanese tsunami records, tree ring studies, indigenous people's stories, and more to create a record of past events; sometimes with unexpected certainty. The last Cascadia event for example occurred around 9 PM or so on January 26, 1700.
You can still see tree stumps on some Oregon beaches at very low tides, which I would presume were submerged suddenly on occurrence of one of the past earthquakes. Here's an article about the "Ghost Forests" in Oregon: https://beachconnection.net/news/ghostfor010912_650.php
Is it just me or are these types of 'do this body movement' metaphors in written featues always too unclear to actually follow along.. are my hands side by side bending fingers to touch? one on top of the other?
I find they often are bad. I don't know if this was written for radio but why not include a simple diagram since we're on the internet? Or is The New Yorker too cultured for that so they can only include snide comics?
In any case I didn't think this one was the worst I have come across. Can you really put your hands side by side with palms facing downward and middle finger tips touching? And if yes, may I see it?
Nothing is bending. Imagine your right hand as South America continent, and left as North America. The middle fingers' tips are touching where both of these two continents are joined by a narrow mass of land.
> Without moving your hands, curl your right knuckles up, so that they point toward the ceiling. Under pressure from Juan de Fuca, the stuck edge of North America is bulging upward and compressing eastward, at the rate of, respectively, three to four millimetres and thirty to forty millimetres a year. It can do so for quite some time, because, as continent stuff goes, it is young, made of rock that is still relatively elastic. (Rocks, like us, get stiffer as they age.) But it cannot do so indefinitely. There is a backstop—the craton, that ancient unbudgeable mass at the center of the continent—and, sooner or later, North America will rebound like a spring. If, on that occasion, only the southern part of the Cascadia subduction zone gives way—your first two fingers, say—the magnitude of the resulting quake will be somewhere between 8.0 and 8.6. That’s the big one. If the entire zone gives way at once, an event that seismologists call a full-margin rupture, the magnitude will be somewhere between 8.7 and 9.2. That’s the very big one.
> Flick your right fingers outward, forcefully, so that your hand flattens back down again. 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.”
https://www.newyorker.com/magazine/2015/07/20/the-really-big...
> Take your hands and hold them palms down, middle fingertips touching. Your right hand represents the North American tectonic plate, which bears on its back, among other things, our entire continent, from One World Trade Center to the Space Needle, in Seattle. Your left hand represents an oceanic plate called Juan de Fuca, ninety thousand square miles in size. The place where they meet is the Cascadia subduction zone. Now slide your left hand under your right one. That is what the Juan de Fuca plate is doing: slipping steadily beneath North America. When you try it, your right hand will slide up your left arm, as if you were pushing up your sleeve. That is what North America is not doing. It is stuck, wedged tight against the surface of the other plate.