Posted on 03/13/2019 9:37:20 AM PDT by Sarcasm Factory
Americans have long dreaded the “Big One,” a magnitude 8.0 earthquake along California’s San Andreas Fault that could one day kill thousands of people and cause billions of dollars in damage. The Big One, though, is a mere mini-me compared with the cataclysm forming beneath the Pacific Northwest.
Roughly 100 miles off the West Coast, running from Mendocino, California, to Canada’s Vancouver Island, lurks the Cascadia Subduction Zone, where the Juan de Fuca Plate is sliding beneath the North American Plate, creating the conditions for a megathrust quake 30 times stronger than the worst-case scenario along the notorious San Andreas, and 1,000 times stronger than the earthquake that killed 100,000 Haitians in 2010. Shockwaves will unleash more destructive force against the United States and Canada than anything short of nuclear war, a giant asteroid strike, or a civilization-threatening super-volcano.
We didn’t even know a megaquake was coming until recently. When I was a kid, growing up in the mid-Willamette Valley in Oregon, earthquakes were California’s problem. Everyone, including scientists, thought us immune. Seismic hazard maps shaded California red and Oregon green. Geologists knew about the Cascadia Subduction Zone, but they thought that the Pacific and Juan de Fuca Plates weren’t locked—that the subduction was smooth, as if the continent were greased with lubricant. University of Washington geologist Brian Atwater proved them wrong in the late 1980s. Oregon had recorded no earthquakes since American pioneers colonized the territory in the nineteenth century, and the native population had no written records, but the earth itself keeps copious records of geologic events, once one knows where to look. Atwater’s first clue was the “ghost forests” along the Oregon and Washington coasts, drowned by seawater, covered by sand and landslide debris, and then exposed by beach erosion. According to tree-ring dating, every one of those forests was buried in 1700. Something extraordinary happened that year. Sea levels can’t rise six or more feet in a year. The coastline itself must have plunged into the ocean. Later, beach erosion exposed yet another ghost forest, in the small town of Neskowin; this one was 2,000 years old.
Atwater then collaborated with Japanese seismologist Kenji Satake, who dug up long-forgotten reports in his own country of an “orphan tsunami”—a violent tidal inundation not preceded by a local earthquake—that also occurred in 1700. Scientists scrambled for core samples of the ocean floor just off the American coast and found turbidites—layers of tsunami debris—that date back millennia and, most recently, again, to 1700, revealing a cycle that repeats itself every 300 to 600 years. The Cascadia Subduction Zone is not quiet, after all: it triggers catastrophic megathrust quakes, on schedule. “A fault that ruptures with this big of an earthquake every few hundred years is ragingly active,” says Yumei Wang, a geotechnical engineer at the Oregon Department of Geology and Mineral Industries (DOGAMI).
A 9.0 megathrust quake is too powerful even to be measured on the now-dated Richter scale. Megathrust quakes are measured instead on the Moment scale. Like its predecessor, the scale is logarithmic. Every whole-number increase represents an energy release 32 times greater than the whole number before it. An 8.0 earthquake is therefore 32 times more powerful than a 7.0, and a 9.0 roughly 1,000 times more powerful.
Of the three West Coast states, Oregon is the most vulnerable. “We’re less prepared here,” says geologic-hazard analyst John Bauer, also at DOGAMI. “Washington has had more earthquakes recently, so they’re better prepared, and California, too, of course. We didn’t adopt a culture of preparation until the mid-1990s.” Portland is also closer to the subduction zone than Seattle or Vancouver, so it will experience more violent ground shaking. And the Oregon coast is considerably more populated than anywhere else in the tsunami’s path. “We’re not overdue,” Bauer says. “But we’re due.”
“...personal firearms and ammunition for keeping the numerous surviving ferals...”
There will be a lot of bodies from natural and unnatural causes. Shoveling won’t be enough. We’ll need a better way.
“Washington has had more earthquakes recently, so they’re better prepared.”, from the article.
The last “major quake” we had was centered near Olympia, WA about 40 miles away from us on February 28, 2001. It was a 6.8 and shook the house for quite a while. It did cause some damage to some structures in the area. It is a little hard to believe that even “earthquake proof” structures more than a story or two high would still be standing after a quake more than a thousand times more intense.
Downtown Seattle and many other low lying highly populated areas are built on top of soil that is prone to liquefaction when shaken violently, so they likely would be completely devastated. Yet our local politicians are playing this slight of hand trick with the global warming scam.
I prefer Idaho myself.
Of note:
A big tsunami will back up the Columbia, flooding all of Portland, out to the coast. And Seattle, especially West Seattle would flood due to the surge up the strait of Juan de Fuca.
Much of the Oregon and Washington coast is low, a dozen or so feet above sea level.
There’d be some real hell up there, no doubt.
Dreaded? Nah, try anticipated.
I still have a few friends living at La Quinta but maybe they will be out of Kalifornicator when the big one hits.
If not, collateral damage for the greater good.S/Off/On/Off/On.
6 more Senate seats? Sweet!
“Oregon had recorded no earthquakes since American pioneers colonized the territory in the nineteenth century, and the native population had no written records, but the earth itself keeps copious records of geologic events, once one knows where to look”
I graduated in 2002 from the Oregon Institute of Technology in Klamath Falls and I find this statement hard to believe. The rocky cliffs along Agency Lake north of Kfalls provide plenty of evidence of up thrusting. We studied these in my Geology class.
Also while I was there we had a 5.7 quake come rolling through one afternoon. Before that I had experienced a couple 4.0 + while living in Seattle in the late 90’s
I believed everything in that movie, except that the fate of humanity would be decided by the acting ability of John Cusack.
Sorry Jimbo.
At one point, I was actually cheering for the earthquake.......................
In Washington, that’s ONLY if Seattle, Tacoma, and Olympia are destroyed and they move the capital to Spokane.
Even though the fault is way offshore, if we get that ‘full 9 rip’, I’ll definitely feel it here. Seattle and Tacoma will get major damage and the coast will be destroyed by tsunamis.
I liked the Woody Harrelson character...................
Your right. For that kind of cataclysm the only prepping item would be a well worn bible.
karma...for all the horrid Oregon commie politics
If ‘karma’ is a motivating factor, then Washington also deserve it...in spades.
How far East of I-5? Since I’m 4 miles East, and two ridge lines North of the Columbia, and can see Mt St Helens on a mildly clear day, I’m mildly interested.
Good thing he made those movies before all the excitement. Otherwise they'd fall flat, like when satire fails because reality beat everyone to the punch.
One of the small Coastal towns in Oregon is doing well in preparation. Besides backup power and water and food they have ordered thousands of body bags.
We’ve got a few ghost trees at a local beach. Them, and the warped strata from events of 44 million years ago, and the deposits on top of them let you know that this too, shall pass.
I don’t know who they think is gonna fill them. I’m in Coos Bay. There’s a good bluff to the south, but the area from Charleston to Hauser pretty much screams tsunami zone.
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