Earthquake Scenarios

#1
The USGS (US Geological Survey) has produced these earthquake scenarios based on what's most likely in their models, for planning purposes.

Their scenarios catalog is here (there are lots of them, some more detailed than others)

https://earthquake.usgs.gov/scenarios/

Here's an Mag 8.0 along the northern San Andreas fault. It would either flat out kill me or render me homeless. Very intense shaking from southern Humboldt county all the way south to Salinas, more than 200 miles! The strongest shaking is along a narrow band near the fault, but I live less than 5 miles east of the San Andreas, so I'd be toast:

https://earthquake.usgs.gov/scenarios/ev.../executive

Here's a Mag 7.1 along the Hayward fault. (It might not be quite so bad where I live, but it's questionable whether my old house could take it.) More localized and worst on east side of SF bay.:

https://earthquake.usgs.gov/scenarios/ev.../executive

8.0 along the southern San Andreas (centered near San Bernardino, so LA might dodge a bullet)

https://earthquake.usgs.gov/scenarios/ev.../executive

Perhaps the worst for LA would be a 7.2 along the Newport-Inglewood fault, because it goes right under LA.

https://earthquake.usgs.gov/scenarios/ev.../executive

And for MR's (and Seattle's) viewing pleasure, here's a Mag 9.4 along the Cascadia thrust fault that would generate a huge tsunami and wipe out all the coastal towns from BC to northern California. Their scenario has it centered in the ocean west of Portland. But it would be so widespread it would be devastating all along Vancouver Island and would even be felt (rather weakly) here in the SF bay area. Its tsunami might be a bigger danger than the ground shaking down here. The tsunami might even cross the Pacific and strike Hawaii and even Asia. One wonders what a tsunami would do as it's forced up the Columbia river and into the Juan de Fuca strait and south into Puget Sound and north up to Vancouver.

https://earthquake.usgs.gov/scenarios/ev.../executive
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#2
(Aug 14, 2019 09:44 PM)Yazata Wrote: . . . And for MR's (and Seattle's) viewing pleasure, here's a Mag 9.4 along the Cascadia thrust fault that would generate a huge tsunami and wipe out all the coastal towns from BC to northern California. Their scenario has it centered in the ocean west of Portland. But it would be so widespread it would be devastating all along Vancouver Island and would even be felt (rather weakly) here in the SF bay area. Its tsunami might be a bigger danger than the ground shaking down here. The tsunami might even cross the Pacific and strike Hawaii and even Asia. One wonders what a tsunami would do as it's forced up the Columbia river and into the Juan de Fuca strait and south into Puget Sound and north up to Vancouver.

https://earthquake.usgs.gov/scenarios/ev.../executive


Most of the simulations since 2011 (Japanese quake/tsunami) seem to claim Portland is safe from the wrath of the tsunami traveling up river. But not the earthquake, of course.

https://www.oregongeology.org/pubs/sp/p-SP-51.htm

Results from modeling a maximum considered locally generated CSZ tsunami revealed the following:

The tsunami reaches the MCR in as little as 7 minutes. The tsunami takes an additional 18 minutes to travel northward up into Baker Bay, where tsunami waves inundate Ilwaco 25 minutes after the earthquake; the XXL1 local tsunami arrives at 31 minutes at Warrenton, 46 minutes at Tongue Point, and at ~99 minutes at Wauna. By the time the tsunami reaches Tongue Point, the tsunami is travelling at a speed of ~37.8 km/hr (23.5 mi/hr).

The CSZ tsunami is detectable upriver as far as the confluence of the Columbia and Willamette Rivers and arrives 4 hours and 40 minutes after the start of earthquake shaking.

The CSZ tsunami contains little energy upriver of St. Helens and can be effectively ignored. Accordingly, a maximum-considered CSZ tsunami will not impact the ports of Portland or Vancouver and no additional measures will be needed to safeguard vessels at these locations, aside from having to deal with the earthquake shaking. The latter is likely to cause navigation hazards where water-saturated sediment liquefies and causes navigation channel sides, levees, and port foundations to fail.


- - -

Tsunami surge could push far up Columbia
https://www.columbian.com/news/2015/feb/...-columbia/

It wouldn’t be until Longview — some 50 miles upstream — that the tsunami would largely dissipate and cause no measurable rise on the Columbia, according to the study. The Portland-Vancouver area would also be unaffected by the surge. [...] Researchers assumed a 9.0-magnitude earthquake for their study. That’s on par with the monster temblor that struck Japan and caused a devastating tsunami there in 2011. That event also saw the tsunami reach far inland through local rivers and cause damage, according to the study. That’s why researchers are paying more attention to tsunami risks facing residents along such rivers, including the Columbia.

- - -

List of cities on the Columbia River
https://en.wikipedia.org/wiki/List_of_ci...mbia_River

Portland to the mouth of the Columbia:

Portland, Oregon
St. Helens, Oregon
Columbia City, Oregon
Kalama, Washington
Goble, Oregon
Prescott, Oregon
Rainier, Oregon
Longview, Washington
Cathlamet, Washington
Astoria, Oregon
Warrenton, Oregon
Chinook, Washington
Ilwaco, Washington

The Dalles to Portland:

Lyle, Washington
Rowena, Oregon
Mosier, Oregon
Bingen, Washington
White Salmon, Washington
Hood River, Oregon
Carson River Valley, Washington
Stevenson, Washington
Cascade Locks, Oregon
North Bonneville, Washington
Washougal, Washington
Camas, Washington
Vancouver, Washington

- - -

The Big One Is Coming. What Will Happen to Portland?
https://www.pdxmonthly.com/articles/2018...o-portland

"Portland International Airport sits on the kind of loose fill that turns to jelly—a phenomenon known as liquefaction—in an earthquake."
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#3
I kinda like this living on the edge of a looming earthquake apocalypse. Call me an anarchist, but I have long had a perhaps all too naive attraction for the ruin of civilization and the reduction of humans to a plight of strenuous daily survival. Ironically I am one of those who are perhaps the least prepared for such. Stranded in a dystopian wasteland with other desperate survivors of an earthquake, life would take on a whole new meaning, forcing me to become things I never knew about myself. I would get in touch with my own inner beast, developing the skills and values of an animal living its life in the jungle. Maybe I live today. Maybe I die today. But at least life would assume this impactful and urgent first hand significance.
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