New West Coast mega thrust fault research = earthquake imminent?

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PokeyDiesFirst@reddit

The sad reality is that most of coastal and western Oregon and NorCal would be inundated or destroyed, and the landscape would be permanently altered. Most of Portland and other coastal cities were built before anyone knew about the Cascadia Subduction Zone, so very few buildings before the 1990's were built to withstand tremors, let alone a big one. To be clear, there have been at least 19 quakes measuring around 9.0 in the past that we've found evidence for in the geological record.

For context, the Cascadia Subduction Zone (CSZ) extends from Mendocino, CA all the way to Vancouver Island, Wa, around 700 miles of fault line. It's currently considered "locked" and not at risk of slipping, but anything can happen and circumstances can change. Rainier and other dormant volcanoes are not expected to erupt if the CSZ earthquake happens, but there is a small chance.

Aside from the damage from the earthquake itself, about 15-30 minutes after it starts a 30-40 foot tall tsunami will hit the ENTIRE Oregon coastline, your mileage may vary depending on where you are and how shallow or deep the coast is near you. This is also aside from runaway fires, flooding, soil liquefaction, landslides, and other terrible things known to happen in the aftermath of a large earthquake. It is unlikely that any rescue will be able to reach you for at least a week, especially if you live away from a city center. Very conservative estimates predict 10,000 deaths and three times as many casualties. Personally, I'd add another zero to both those numbers- it will largely depend on what time of day it occurs. Nighttime means a much larger percentage of people in structures who become trapped while asleep. Daytime has better odds for lower casualties and deaths.

If you live in western Oregon or NorCal, have a plan. Get enough bottled water and nonperishable food for a couple of months. Wouldn't hurt to try to plan a "long term hiking trip" to get some extra antibiotics from your primary care provider. Plan for total power and water grid failure, they will not be coming back for many years if ever. Portland, Eugene, Astoria, Cannon Beach, Roseburg, Medford, Ashland, pretty much any city within 40 miles of the coast will be severely damaged with high death tolls.

The National Guard already have plans to stage in Bend should the big one happen. The Sisters provide some measure of protection for the area and it should be somewhat minimally affected. Bend will likely become the de facto capital of Oregon in the aftermath, with state government and relief efforts moving there. We could expect that Redding will become a staging area for relief along the California coastline.

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OxytocinOD@reddit

Would Sacramento be inland enough for a fair bit less damage? Looking to relocate there for work in Medicine and expect if it occurs it’d do significant damage.

How much damage do you estimate that area would endure? Would a newer house that is earthquake resistant go a long way in preventing damage to it?

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Allumina@reddit

We’re pretty safe in Sacramento as far as I’ve ever heard. I’m more worried about fires and floods.

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OxytocinOD@reddit

Very good to hear tysm

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Allumina@reddit

Where are you relocating from?

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OxytocinOD@reddit

Currently from San Antonio, TX.

I’ve lived in Chicago, Brooklyn, San Diego, Loma Linda, Austin TX, and now here. Grew up in a tiny town with 2000 people in Michigan. Since 16 have lived in cities.

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Allumina@reddit

I think you’ll like sac, especially if you’re the outdoorsy type. We’re just a couple hours from beaches or snow, close to national parks, we’ve got a killer river scene here, soccer league, AAA baseball team (plus now the A’s for a couple years), amazing basketball team and culture, the weather is pretty decent. It’s a good place to call home. Just getting a little expensive because a lot of people from the Bay Area brought their money during Covid and WFH.

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OxytocinOD@reddit

That sounds amazing and right up my alley! Thank you so much. Yes, I noticed it’s a bit more pricey than pre-covid but I’m excited to be close to rivers, mountains, lakes, and forests again! My wife and I have been scouting it out and are excited for the next leg in our adventures.

I’ll be working at UC Davis now and maybe Kaiser Sac/Roseville in the future. I know East Sac is fairly high cost, what so you think the value of the homes there are? What to you think of try to settle into an area like Wast Sac vs new builds vs elsewhere?

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Allumina@reddit

I should circle back on Roseville… don’t read too much into what I said, it’s still nice there and there’s some very high end stuff in Roseville. Plus, if you’re going to work at Kaiser, that’s where the nice one is. Both of my kids were born at Kaiser Roseville and it’s a wonderful facility (and always expanding).

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Allumina@reddit

West Sac is pretty cool and there’s a lot of new construction there and it’s a straight shot into downtown/old sac which is cool.

Roseville was always the “nice new” area when I was a kid but it’s actually getting a little run down now.

The new/nice/high dollar stuff now is Folsom and Eldorado Hills, but it’s pricey and there’s a lot of Bay Area people up there and they just bring a different vibe that I personally find abrasive. Plus it’s a fair stretch up the hill so if you’re commuting into downtown or something you’ll have some freeway driving ahead of you.

Stay away from south sac, that’s the hood. Me personally I’m pretty comfortable down there but it’s got some NOTORIOUSLY rough areas.

Elk Grove is pretty meh… it’s a giant expansive suburban hellhole where every single shopping center and subdivision of track homes is indistinguishable from the next. And it can be pretty ghetto because it’s directly next to and basically connected to South Sac now. EG seems like the place that collects the people who scrape together just enough money to crawl out of the hood. People will argue with me on that but idc, my wife is from EG so I’ve spent a lot of time there. EG used to be super cool and rural actually, but it’s expanded so rapidly that’s it’s basically just part of Sacramento now.

Further South you’ll find Galt, which is where I grew up, is still very rural and I absolutely love it there. But still, it’s growing and with EG’s rapid growth they’ll be connected soon.

East sac is old money and very pricey, and there’s a lot of young adults in the non-mansion parts because that’s essentially where Sac State (CSUS) is, so there’s a ton of new dense student housing being built.

Mid town is kind of the hip area but it’s also expensive and you’re not going to have any kind of yard. It’s all small old houses on small lots or new really nice apartments. That’s going to be your area is you want a real urban scene.

Citrus Heights is pretty meh, very generic suburbia, pretty ethnically diverse.

Orangevale is cool because it has some semi rural stuff, you can get some decent sized property and it’s not too expensive but you’re super land locked in a lot of it. I’m talking like a 20+ minute drive just to get to a freeway.

Me? I’m smack dab in the center between Fair Oaks and Carmichael, right by the river. I love it here, the traffic isn’t bad, the people are chill, it’s super quiet at night, really close to either of the major freeways. I would have a hard time picking somewhere else to be.

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Sxs9399@reddit

PBS has some great videos on the topic: https://www.youtube.com/watch?v=76b_WGzCI54

In short most of the catastrophe will be due to flooding and that's limited to \~10 miles in land. Note the keyword "catastrophe", there will be blocks that are absolutely destroyed, damage will extend inland but may be more similar to the damages seen after a cat 3 hurricane. Sure some houses will get destroyed but not every house in a 10 mile wide strip.

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OxytocinOD@reddit

Makes sense. I really appreciate it and that is one scary thought for us to live through regardless of which part of US we’re in.

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onorbit247@reddit

On the bright side, maybe they'll reinstate the ferry service between SF up to Seattle. Used to cost $5 for a steamer ride from Ft. bragg down to SF along the coast, 1800s.

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Antilock049@reddit

Honestly that would be a fun trip!

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LikwidDef@reddit (OP)

I'm super down!

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IagoEliHarmony@reddit

Need to point out here that you're missing a huge swath of impact - WA state. the Cascadia Subduction Zone runs CA to Vancouver Island, CANADA.

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PokeyDiesFirst@reddit

D'oh

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adoptagreyhound@reddit

Using the recent event in NC as an example, if you're near the coast, rescue won't likely reach some areas for up to a month or more.

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aipixelpioneer@reddit

Medford and Ashland have so many mountains in between. I highly doubt the tsunami is going to reach that area

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bluecoastblue@reddit

Vancouver Island, BC not WA

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Feeling-Intention995@reddit

Drill more oil

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LikwidDef@reddit (OP)

Do a barrel roll?

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boofingcubes@reddit

Drill baby drill 😈

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therapistofcats@reddit

Why change the title from "could be imminent" to "earthquake imminent"? Especially since the article is from several months ago, we must be talking geologically imminent, not human timescale.

Is this really prepper intel? Pretty sure everyone out west is already aware large earthquakes are geologically imminent.

The article doesn't even give a real timeline other than "roughly every 500 years, last one was in 1700"...cool so we might all be dead by 2200 anyway.

So how is this prepper intel? How did this change anyone's preps or give new useful information?

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LikwidDef@reddit (OP)

I dunno brother. I saw the article and felt compelled to post it. I didn't mean to seem glib

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OtisPan@reddit

This sub is 98% useless submissions these days, TBH.

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Obvious_Key7937@reddit

As a former San diegan, good. The West coast is the Mos Isleys of the world. Portland, Seattle, all of coastal Cali... just eww.

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BigJSunshine@reddit

As a coastal Californian, let me be the first to say:

gif

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LikwidDef@reddit (OP)

Right on!

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LikwidDef@reddit (OP)

As a San diegan as well, fuck off! I love cantinas

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BigJSunshine@reddit

Just read an article on research being done in Iceland regarding the impact of receding glaciers on volcanic and/or earthquake activity. If the theory holds weight, I wonder how it might affect earthquakes, or even volcanos in the west.

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LikwidDef@reddit (OP)

Happen to have the link? I love glacial articles, let alone them telling me about potential volcanic issues

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Nick2-6@reddit

Nothing. Ever. Happens.

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TediousHippie@reddit

The likelihood of it happening today is 0.000545% or roughly 1 in 182,500. The likelihood of it happening is 100%. "Nothing ever happens" is normalcy bias.

If you live in Bellevue, it doesn't matter at all. If you live in Aberdeen or Port Townsend it matters a lot. A 1:6 chance that in your lifetime that your family and everything you've worked for could be destroyed with basically 5-10 minutes warning are not odds I'd want to bet on.

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OxytocinOD@reddit

Very good perspective. Would Sacramento CA be fairly safe or hell no?

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TediousHippie@reddit

I read some book that involved a comet impacting somewhere off the California coast, creating a global catastrophe that included a megatsunami that inundated central California and turned it all into an inland sea. That's a super remote possibility and I wouldn't put that on my list of worries. Even if the Sacramento River ran backwards it wouldn't be immediately threatening under almost all likely conditions. Also, you'd possibly feel a deep subduction quake, but you'd be more likely to be feel the supply chain results from a big San Andreas quake. Just my 2cw.

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OxytocinOD@reddit

Really good information. I appreciate it a lot.

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BuilderUnhappy7785@reddit

Bingo

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BigJSunshine@reddit

Thank goodness

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or_iviguy@reddit

to.me.

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RascalBSimons@reddit

Asheville, NC would like to remind you, never say never.

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thehourglasses@reddit

Last year featured the most billion dollar natural disasters at 28. This year is going to far exceed the total cost of last year’s disasters since we have the absolute devastation of Helene to factor. Your statement is demonstrably false and really just indicates your unserious disposition.

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PokeyDiesFirst@reddit

Until it does. We have enough evidence in the geological record for at least 19 8.0+ earthquakes in the area, the last one occurring in 1700.

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Nick2-6@reddit

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PokeyDiesFirst@reddit

Okay buddy

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Not_kilg0reTrout@reddit

"imminent" in geological terms is a very long time compared to something imminent in a human life time.

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thrombolytic@reddit

That is mostly true, but this particular fault has an average interval of big quakes (>8.0) every 400-600 years. The last big quake was in 1700. So it could be tomorrow, could be 300 years from now. It is definitely not outside the range of possibilities to happen in our lifetime that this fault causes a major quake in the PNW. "Currently, scientists are predicting that there is about a 37% chance that a megathrust earthquake of 7.1+ magnitude in this fault zone will occur in the next 50 years."

https://www.oregon.gov/oem/hazardsprep/pages/cascadia-subduction-zone.aspx

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OxytocinOD@reddit

How devastating would that be to the bay area and upward?

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thrombolytic@reddit

The Juan de Fuca fault goes from Vancouver Island to Cape Mendocino, so AFAIK the bay area would not be severely impacted directly by the earthquake. It is theorized to significantly impact Vancouver, BC, Seattle, Portland, Salem, Eugene, and the coast of BC, OR, NorCal and WA. I've read estimates of a tsunami impacting as far as miles inland from the coast and the type of fault and quake leads to predictions of the ground west of I-5 experiencing liquefaction.

https://www.inlander.com/news/the-next-cascadia-subduction-zone-earthquake-will-be-devastating-spokane-county-will-help-rally-resources-and-could-become-home-to-thousands-28417573

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OxytocinOD@reddit

Liquefaction of the West Coast. Well that is horrifying.

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thehourglasses@reddit

I hate being on the wrong side of a 60/40 — lost a lot of money in poker feeing good about the 60 only to get wiped out by the 40

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TylerBlozak@reddit

Aren’t anatomically modern humans (250,000 ya) about a few seconds on the 12-hour geologic clock of Earth from its inception?

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RiceFriskie@reddit

The chance is at least 37% of a 7.1 magnitude mega thrust earthquake in the next 50 years according to Oregons emergency management department. A 40% chance of a 8.0-8.5 mega thrust earthquake in the next 50 from USGS. And a 7-15% chance of a 9.0 mega thrust earthquake in the next 50 years from the Oregon resilience plan.

Safe to say it's not unlikely within the next 50 years to happen. Heck, even this year it's a uncomfortable probability. Everyone alive this moment has a chance of experiencing this, even if they die in a week there's a chance they might experience it. This isn't somthing to brush off, as it won't be just the PNW being devastated. All the industry, wood and imports will be wrecked too for months if not years due to the devastation.

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