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.”
Mine are all out now, except for some in Napa. So I’m good.
So should we be buying up potential ocean front property in Utah?
Interesting research to uncover the “ghost forests” and tie that to “orphan tsunami” records in Japan. That’s some good thinking.
I noted the statement “Sea levels can’t rise six or more feet in a year.” The author is obviously a “Denier” who hasn’t gotten with the program.
We can prevent this by government confiscation of wealth, labor, and property, the burning of Bibles, abolition of meat, and pumping water slowly out of the ground.
Remember the old song by Shango..
Where can you go,
When there’s no San Francisco.
Better get ready to tie up the boat,
In Idaho.
No worries. Higher taxes should take care of that problem. That and complete iron fisted control of people.
Dang. Just when CA residents moved there to escape “The Big One.”
The entire movie was goofy........................
Those precautions should be worth a lot when an earthquake a THOUSAND times larger hits. :)
Just prepare to be..wait for it...
DEAD!
:)
Paging Irwin Allen...
No kidding, a limousine performing jumps that would amaze Evil Knievel.
That’s one of my favorite drinking movies. Every time a million people die, I take a drink. I snuck a bottle of scotch into the theater for an afternoon showing of “2012” and was obliterated by the end.
That part at the end where Danny Glover is about to be smashed by the tidal wave and the aircraft carrrier, I stood up and yelled (slurred), “It’s the BIG ONE ! I’m coming ‘Lizabeth !”
Here’s the executive summary. On a date and time unknown, but at some point in the future, everything west of the I-5 corridor is going to be obliterated. At which point, California, Oregon and Washington will become Republican states.
Note: FR is in California.
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