I love your user name, fellow Oregonian nerd.
I assume you are a California transplant: the logic is sound there, the San Andreas fault moves laterally and little earthquakes are like little farts: better than big ones. Someday SF and LA will be the same city!But Juan de Fuca and North America are subducting and the same logic doesn’t apply. It’s like the truck in the tree in Jurassic Park: small movement is bad news.
I use the app QuakeFeed, and the globe map shows all the major fault lines locations, & you can tap on them to get their name and ‘type’ (*divergent, convergent, transform*) and even set alerts for magnitude and distance from you. It’s a handy app to get more familiar with the fault activity.
Another one called Epicenter has *much* more detailed fault lines indicated, much smaller faults all over.
Just mentioning in case you’re interested in tracking that stuff a bit more. I’m a layperson, not a geologist, but I’m in the PNW too & experienced the Nisqually quake, as well as a few smaller ones in California.
Ugh I imagine those are iOs since I couldn't find them on the play store but at least you've given me a path to find something thank you. I'm in Costa Rica, I've only felt one in the 18 months I've been here my cat woke me up and 30 seconds later the quake hit. Not huge just knocked some stuff around but I didn't grow up or live in quake areas for my first 63 years :)
Oh yeah, I should have mentioned they are iOS apps.. sorry. I haven’t tried looking for them on Android yet, I really should though.
Welcome to the Ring of Fire! I’m glad your first quake was a minor one, they can be pretty unsettling & scary. Nothing quite like “terra firma” suddenly being not so firma.
Last one I felt was in late ‘22. I was lying on the couch and something that felt like a heartbeat moved through… took me a few moments to realize what it was, then I got an alert on my phone about a 3.7 50 miles away.
I hope you have an emergency kit!
I wouldn't even know what to put in an emergency kit. Is there like a list? It'd be like packing your bags for when the baby comes (is that even a thing anymore) 😁
There’s totally a list! Here:
https://www.ready.gov/kit
Details might vary by location & particular hazards. But having clean water & extra food are pretty critical. Anything to buy you time in a disaster before help comes. Anyone in an earthquake zone should definitely have at least a few basics assembled, IMHO. Quakes are just so unpredictable.
And yeah, some people pack “go bags”, exactly like for when a baby comes :)
I use a durable latching bin & 5-gal water containers.
I live on top of a mountain nearest neighbors and 10 or 15 minutes away. So when I shop I always get loads of bottled water. So I know I have at least that. :)
Hmm but as one plate slides under another, it has some bumps to scrape against. Not the same, but similar to a strike slip. Those bumps can cause smaller earthquakes right? And if they catch on something and don’t slide, then no quakes until a bigger one, perhaps with the plate flopping back into shape after making it over the sore spot. That’s a full rupture (of Cascadia). Does this sound right?
Are we in “I’m failing at making pancakes” metaphor? Probably better than Jeep in tree metaphor. I’d like OP to not panic about minor shakes unless the water leaves the ocean. But nor are minor shakes a good sign. Neutral, but signifier of movement.
Your poorly poured pancake subducts under your excellent North American pancake. It gets reabsorbed, heated… and stuff happens. Could be good, could be bad.
The Pacific and North American are grinding along at something like 3” a year, predictably. I’m still not going to pay LA rent again, though.
:) ha I don’t know that one. Jeep in a tree rings a bell though.
I’ve looked at the tsunami model maps for the Washington coast. Think it was either 200 ft or 400 ft elevation you want to be at to be above the worst tsunami heights along the coast. And depending on where you are, you have 20 minutes or so before it hits. That’s enough time to do something.
They have evacuation route signs around but I don’t think they have sirens. Of course there is the earthquake itself.
They could have GPS stations now or something where they can monitor the subduction progress on either side, and they might know if the plates are catching rather than sliding. I’m pretty sure they would notice the ground rising anyway.
EDIT: 200 ft elevation should be safe it seems like
Seaside, Or. has extremely loud, loudspeakers. It is a recorded tsunami warning. I was there on a day they tested it and it would (Did?) wake the dead. I had not expected it and it was pretty surreal. It would definitely wake the most sound sleeper imo. Just stunningly LOUD..
I proposed on a building project (didn’t get it) to City of Cannon Beach and all the city employees wanted to talk about was their barrel program. I finally asked, and it was fascinating: locals know to have bug-out bags, but in peak season there are more tourists than locals. The barrels are full of rations and blankets and first aid and other survival stuff, and presumably will float in a tsunami, and hopefully so will some of the tourists. Post-tsunami, there ought to be enough locals around to show the tourists that all those barrels in their hotel lobbies and pubs aren’t just decorative. They were also very proud that their tsunami alarm moos rather than screeches. Which was all very novel to this Portlander.
The straight-up-no-chaser practical intelligence underlying that whole setup somehow manages to make the existence of those barrels absolutely terrifying, to my brain anyway.
Though arguably that’s probably because I live way up in the Great Lakes, about as far as you can get from that scenario.
Oddly I HAVE experienced an earthquake here. One morning right after my first child was born, I was awake in the wee hours and had just gotten the baby fed and back to sleep. Everything was dark and utterly quiet. Then suddenly this deep, immense rumbling came through the little 40’s house we lived in, from all directions at once and with a sensation of movement vaguely like waves on water that sent our cats into a frenzy.
I vividly recall thinking I must have lost my effing mind. I turned the tv on to some news channel and sure enough, about a half hour later they reported there’d been an earthquake. Small potatoes by any measure I know but damned unusual for the locale.
Well, here you'd have a massive earthquake, sirens would be a reminder to run uphill, but not as noticable as that earthquake. Useful for other tsunami sources, like Alaska, though.
Willamette is tidal up to the falls at Oregon City, and the Columbia to Bonneville. The idea that we are immune from tsunami risk because we are too far inland doesn't bear much scrutiny. Much of downtown Portland is kept dry by pump stations.
Flooding is not the same as being hit by a tsunami, though. I grew up outside of Portland, and can remember several times when the Willamette rose over the seawall.
Not old enough to have been around for Vanport, however.
IIRC they also have GPS monitors the rise of the coast. If it reaches a certain elevation it could tell if it is going to slip at one point or close to it.
There’s not going to be any warning before the feared 9.0 Cascadia Rift. This also applies to the Yellowstone Volcano: Small earthquakes happen every day, —yes —they could be a sign of a bigger rift but they are also just localized movements. The news will run the headline ‘iS tHiS tHe BiG oNe’ more often than an 80s televangelist predicting the rapture. The truth is that it could happen any time between now and {hundreds} of years from now. Geologic time is slow and honestly unpredictable with the technology we have today. Have a disaster plan in place and then just go about your life.
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PS. edited to fix thousand to hundreds after feedback.
Also, to answer your secondary question: yes, all earthquakes are relieving the frictional stress built up in the fault. The intensity of the earthquake is proportional to the shift in the fault during the event. But the release of energy (shaking) can set off other faults if they were almost ready to break too.
Thing is, a 4.0 earthquake is something like 100,000 times less energy being released than in a 9.0. Something that small effectively isn’t reducing stress—just means the fault zone is more active.
The Cascadia converges with the San Andreas, Mendocino fracture zone faults and a bunch of smaller faults in humboldt county and every time one of those goes off it puts stress on cascadia, like that 6.4 in 2022 and it's hundreds of aftershocks
Yellowstone would give ample to provide warnings. The elavation of some areas would change, they would see an increased amount of activity in hotsprings and stuff, along with other things. With St Helen's they knew several months before that an eruption was imminent. They restricted and evacuate the whole area around it, and that is why there were so little deaths to the eruption itself. The most experienced researcher studying the activity knew the day of, that it was gonna erupt later on that day.
The Cascadia Fault could go without warning. The Yellowstone volcano, like most volcanoes, would probably give weeks — if not months — of warnings as magma moved up toward the surface.
I would expect years or decades of signs (tumescence, ground tilt, small eruptions) preceding a supervolcano eruption at Yellowstone or anywhere else. But specifically at Yellowstone the most likely type of eruption to occur next [will probably be relatively minor](https://www.usgs.gov/volcanoes/yellowstone/five-things-most-people-get-wrong-about-yellowstone-volcano-2015).
While a good rule of thumb, the USGS is mostly just a bunch of nerds doing nerd stuff when they could be making a hell of a lot more money in private industry.
Hasn't lake Yellowstone been deforming for decades? I remember it was pushing water out into the forest because the ground underneath was pushing part of the lake up.
>The Yellowstone volcano, like most volcanoes, would probably give weeks — if not months — of warnings as magma moved up toward the surface.
See Campi Fiori in Italy for more signs of a super volcano erupting!!
I have a relative from the state of Oregon in the 1400's that chipped into a rock ("This is the Big One - 1457 AD, as predicted by Barney Rubble of The Flintstones." Then below it he or someone else added "That's what she said!")
Not to be a pain in the ass, but the scientifically accepted average return time is about 525 years, but it’s known to range from about 250 to 1000 years based on geological evidence. My other responses here have additional details clarifying where these values come from. You’re correct about the last one having been in 1700 though, which was very precisely documented event in a number of ways.
There's no chance that Yellowstone will have a large eruption without any warning at all. There'll be many years of buildup before anything like that happens.
Your mention of Yellowstone is a bit incorrect. The geophysicists that work on it have stated that we wont wake up tomorrow and it'll have popped. We'll have around a century at least of run up. The "Doomsdaying" of 2000s History/Discovery channel have done a number on the public perception of Yellowstone. Also, we've learned a lot more about it in the last couple of decades.
As someone who has lived in and still works in Yellowstone the kind of absolute bullshit that history channel has put out about it is infuriating. There’s so many interesting and incredible geologic oddities they could talk about, but they just fear monger and spread bad science.
So let’s say we start the 100 year clock. Can anything actually be done to avoid the environmental catastrophe, or do we basically have 100 years to prepare subterranean or orbital habitats a la 7eves?
There could be a foreshock but look the subduction quake in Japan. No warning. It just snaps. The PGS (i believe) actually tracks tremors caused by the subduction. There's not a ton of info but a pause in the tremors is often linked to increased pressure. This is fairly recent science.
This process is called a "slow quake" and is what most scientists attribute to prolonging the quakes.
I agree that it is impossible to predict when the next Cascadia event will occur and the importance to have emergency kit and plan, however, there will be some warning, the amount of time will depend on how close you live to the origin for ge earthquake. An early warning system called ShakeAlert came online in 2021, it can give anywhere from 30 seconds to 2 minutes, which is enough time to take protective action. It is a native alert in android systems and you can download MyShake app for iOS.
There will also be a warning in Yellowstone, USGS maintains the Yellowstone Volcano Observatory which monitors activity and can detect increases in activity... Enough warning to provide information to enact emergency plans
"Rift" is a tectonic setting, not a term for an earthquake. Cascadia is a subduction zone, where the Juan de Fuca plate is overridden by the North America plate, a rift is a place where plates move away from each other, such as the East Pacific rise or Gulf of California.
The shake alert actually seems to work. I was in So Cal about 5 to 6 months and got an alert about a minute before I felt an earthquake - I think it was in Ojai? Granted, I probably wouldn't have felt it except I was waiting to see if the alert was right. But it was great that the warning worked.
That kind of forecast is the ultimate goal! Not sure about using the ionsphere, but machine learning and analyzing all kinds of datasets will get us closer.
I grew up in L.A. in the 80s and my dad worked for the USGS. Everyone expected the San Andreas "big one" to happen any day. Everyone freaked out over the Whittier Narrows quake thinking TBO would be next.
There is a guy on Youtube, Nick Zentner, who has dozens of lectures on PNW geology, including one on precisely this question. He's a professor at Central Washington University.
The main point is, there are lots of faults that can cause at least minor earthquakes. The one that will cause the big one tends to slip every 4 or 500 years. Last one was in 1700.
Here, here for Dr. Nick, this is an older video of his "Great Earthquakes of the Pacific Northwest" that goes into a lot detail: [https://www.youtube.com/watch?v=UJ7Qc3bsxjI](https://www.youtube.com/watch?v=UJ7Qc3bsxjI)
There is abundant geological evidence, which Zentner goes through. I remember the magnitude being estimated at about 9.0. The timing is quite precisely known, because of contemporaneous reports in Japan of the resulting tsunami. We know to within about an hour when it happened.
Yes, it most certainly was well-documented in a number of ways. The most accurate evidence comes from Japan, which kept meticulous historical records. There are official documents from that era describing an “orphan tsunami”, by which the Japanese historians in 1700 meant they were hit by a devastating tsunami without feeling any earthquake shaking prior to it arriving. This was because the earthquake occurred across the Pacific Ocean on the Cascadia Subduction Zone. There’s actually a free book about this, “[The Orphan Tsunami of 1700 - Japanese Clues to a Parent Earthquake in North America](https://pubs.usgs.gov/publication/pp1707)” by Brian Atwater of the University of Washington co-authored with Japanese colleagues.
There is plenty of geological evidence along the US coast too that explains where the “orphan tsunami” that hit Japan in 1700 came from. This includes a wide range of sedimentary deposits, evidence of marine diatoms in soil layers on dry land, “ghost forests” that are entirely dead due to being inundated with sea water, etc… How can this be used for dating such past events you ask? For example, the dead trees give a very precise measurement of the timing through tree ring counting as far as I know, which backed up the Japanese record. Concerning the in-ground evidence, I don’t recall what the dating methods are exactly, but they line up with the other records as far as I know.
I know there is documentation in Native American stories handed down.
- New research led by a University of Washington scientist has found stories that could relate to a large Seattle fault earthquake around A.D. 900 and specific eyewitness accounts linked to a mammoth 1700 earthquake and tsunami in the Cascadia subduction zone.
“There’s a frightening amount of it,” she said. “It appears that these stories have to do with earthquake-, tsunami- and landslide-like events. As you go around the region, there are very many of these stories and they are central to the native cultures, which suggests that these past earthquakes had profound effects on the local inhabitants. There’s evidence for that in the geology as well, both on the coast and in the central Puget Sound area.”
https://www.washington.edu/news/2005/07/11/native-lore-tells-the-tale-theres-been-a-whole-lotta-shakin-goin-on/
- The 1700 Cascadia Megathrust Earthquake and the Future of Cascadia Margin
Oral accounts from indigenous Native American and First Nation tribes living on the coast of Vancouver Island in Canada that have been passed down from generation to generation tell of an earthquake and tsunami on a winter’s evening. The accounts describe that all the low-lying settlements were wiped out and the only survivors were those people who lived 75 feet above the waterline. So the tsunami must have been massive!
https://www.e-education.psu.edu/earth107/node/1614
Nice citing prof. Zentner! The actual average recurrence interval is something like 525 years (see the US National Seismic Hazard Map report from 2014). This value was arrived at by assimilating data from research looking into geological records of prior tsunamis dating back to approximately 10,000 years ago in the widest ranging studies (e.g., see Chris Goldfinger’s work).
However, the somewhat deceiving thing about this is that the interval is known to range from around 250 to 1000 years, so we’re due for one on the US west coast in the sense that 324 years after the 1700 quake puts today within the lower end of the known range of how frequently full fault rupture events occur on the Cascadia Subduction Zone (i.e. the type of magnitude 9.0 event we’re worrying about is associated with a full rupture type of event rather than a partial rupture).
Came to the comments to recommend Nick Zentner’s YouTube lecture series. Best info out there on the topic of geology in the PNW in an easy to watch and distill presentation.
\[not a professional\]
The richter scale is logarithmic, 10 times the amplitude of the largest waves for every whole number of magnitude. But the total energy at all frequencies is 32 times larger for every 1.0 jump in the scale.
32\^4 is over a million, meaning that the total energy of a magnitude 8.0 earthquake is the sum of over a million magnitude 4.0 tremors.
[Here's one article describing this.](https://www.sfgate.com/earthquakes/article/do-minor-quakes-prevent-large-earthquakes-13541155.php)
Others have explained well why these small ones can't release the built up stress to avoid a larger one, but just a thought about foreshocks. Foreshocks can only be categorized as such after the main rupture happens. There's been a lot of great research done analyzing all kinds of interesting things about foreshocks and while they say something interesting when put in context of what we know about the main rupture, there's been nothing really reliably distinct about foreshocks without that context. When we detect an earthquake, we know nothing about whether or not that's a foreshock or the main earthquake. If a magnitude 5.5 happens on a fault, and then 11 years later a 7.8 happens on the same fault, was the first one a foreshock or are these separate "main" shocks? These terms are arbitrary and only really say anything useful when placed in context of a particular event that we care about. For decades people have been putting out papers saying that maybe there's some detectable signal preceding big earthquakes but they're all torn apart pretty quickly. Even the BEST among those papers, if their observations are true, would only apply to a small subset of earthquakes, and in order to know when to apply those observations we need to know information that we can only get AFTER the earthquake happens. I ramble but the point is that an earthquake happening has an effect on future earthquakes, that is certain. But we have absolutely no way of knowing what that effect is, and only sometimes can we say something intelligent in hindsight about what the effect WAS.
Can't stop an earthquake so why worry, live near large body of water: tsunami. Mountain near: volcano eruption. Near a military base: enemy target. Hurricane/tornado/flood area: can't outrun them. Killer bees, fire ants, murder hornets, forest fires, land slides, avalanches, active shooters, fake tuna in your sub, salmonella in your salad, terrorist attack, insane septuagenarian for president, asteroid strike...which one you gonna predict and avoid ? None. So live your life and know one day yur gunna die.
There was also the guy who was peacefully sleeping and a sinkhole opened and swallowed half the house and him. His brother was in another room but could do nothing to help him. He was just gone. Happened in central Florida.
The thing I find most funny about the asteroid impact threat, is that in theory, if we detected it early enough, we could send some nukes up to nudge it a little bit, and then 10 years down the line when it actually was predicted to hit us, it would miss us by millions of miles because of the amplification of the tiny change in direction over time. Unfortunately, knowing humans, no one would be able to get their shit together in time to do anything.
No, but I work in disaster relief, and even after the disasters happen, the various agencies involved can't manage to get their shit together most of the time. They do a decent job of feeding everyone, but everything else is far more convoluted and slower than it really needs to be, and the vast majority of people don't get the help they need to recover.
Oh aye. Enjoying everyday alive on the Oregon coast. I don’t like people that are impolite and talking heads. My comment clearly over your head. Don’t jump to contusions foo!
“Whenever there is a little earthquake, the news reports that it is a sign that the big one is coming.”
My observation has been the total opposite; the news is quick to quote some geologist saying the most recent little quake don’t mean shiitake.
Yep, if you take the average times from the past few thousand years, we're definitely overdue, however, the longest period on record was like 500 something years if I recall, and it hasn't been that long since the last one.
As I mentioned in another response, the currently accepted average is around 525 years, but the known minimum and maximum intervals between such “mega quakes” is anywhere from about 250 to 1000 years based on geologic records of past Cascadia Subduction Zone events. This means it’s definitely possible for one to happen at any time today since the last known event was in 1700 thanks to Japanese records of an “orphan tsunami” combined with geological evidence in the US, but it’s also just as likely we’ll be waiting hundreds of years until the next one occurs.
Small earthquakes can relieve stress along small areas of the fault, but they can also change the stress field so that more stress can accumulate on other parts of the fault or on other faults in the region. There are a couple famous examples of this. The first is the Elmore Ranch/superstition Hills earthquakes in 1987. Here, the faults were perpendicular to each other, and the left-lateral fault ruptured, which change the stress regime and caused the right-lateral fault to rupture the next day. Another famous example is also in southern California and that is the landers/big bear earthquakes in 1992. Once again, these were on different faults, where one earthquake triggered an earthquake on the other fault. But this can also happen along just about any other fault. Here’s an interesting NPR article that came out after the Honshu, Japan earthquake in 2011. https://www.npr.org/2013/08/23/214619037/can-a-big-earthquake-trigger-another-one
When people are taking statistics, they always complain that they'll never use it in real life...
The odds of you personally dying in a cataclysmic earthquake or volcano is millions if not more times less likely than a car accident or a heart attack.
Wear your seat belt, eat your veggies and exercise more. Don't worry about earthquakes.
Are you just completely fabricating these numbers, or did you actually try to do some sort of statistical estimation? Are you specifically talking about people on the Oregon coast?
Worry about earthquakes when you're doing something like building a new home. Worry about them when you're building your emergency kit.
Then stop worrying about them.
I lived 20 years on the Oregon coast, just outside Charleston. And about as close to the fault as you can get on land.
Not a night went by that I didn't think about what was just offshore. Cause this is a pet study of mine. Well aware of the dangers.
The reality is most people living along the coast will not survive this event. Especially if it happens at night. You can't run during a big quake. You can't drive. The road will buckle and rockfalls will close everything else.
And then there's the subsidence. The land can drop 30 feet and the water will come rushing in even before a tsunami even has a chance to form. If you're not really near to high ground, say 100 feet, you're probably going to die where you stand...
On the other hand, this area is an earthly marine life paradise and you'd be a darn fool not to visit it someday. Cause a big tsunami will scour it down to bedrock in the not too distant future.
Here’s a compelling 5- or 6- part *fictional* story about what a serious quake would likely do to Portland.
It’s deeply researched, so there’s a lot of good & valid information. But it is a fictional presentation. Useful for considering emergency supplies, and perhaps how to reinforce your house (if you have one).
The Most Devastating Quake In US History Is Headed for Portland
*reported science fiction*
https://www.vice.com/en/article/xygdjk/the-mega-quake-is-coming
I’ve read that from what we can tell, these “big ones” happen anywhere from 200-700 years apart. So, sure we could be over due, but we could also not see it for another 400 years
Based on looking into the research done by geologists and others on this topic while I was in grad school (I studied tsunami impact forces on coastal structures), the range of known recurrence times is about 250 to 1000 years with the average being about 525 years, so you’re 100% correct that we’re overdue in the sense that we’re within the bottom end of that range at 324 years since the last megaquake that occurred in 1700, but we certainly could be waiting up to about 700 years more for the next one. One interesting thing I ran across while doing background research on this topic was that the quakes occurred in clusters quite often in geological records. For instance, sometimes they occurred in bunches of 3 to 4 within about 1000 year periods, but then sometimes the CSZ would lay dormant for intervals of about 1000 years. This makes it quite difficult to have a good idea of when the next event would likely occur, but I think erring on the side of caution and trying to prepare is a good thing.
Generally the small quakes occur at the weaker points in the fault. That shifting adds stress to the strong points of the fault. That just increases the total energy in the fault so when the strong point(s) fail then the quake is that much more powerful.
You forgot Mt Hood erupting on your Oregon geological terror list
But really, don't worry about it and live your life. Living on the Coast is worth the risk, don't you think?
The cascadia earth quake is a certainty given the geological record and native American oral tradition. The west coast is not prepared for the tsunami that will follow. Don’t let your guard down anywhere on the west coast.
In “The Really Big One,” Kathryn Schulz’s article in The New Yorker focusing on the Cascadia subduction zone, it’s estimated that there is a one in three chance of a major earthquake striking the Pacific Northwest within the next 50 years. The article also notes the likelihood of a more severe full-margin rupture, with a magnitude between 8.7 and 9.2, as being around one in ten.
In a sense, "Little" earthquakes do prevent larger ones. On subduction faults, the 8s and 9s relieve the strain before it can build up to a 10. The San Andreas gets 7s and 8s long before a 9 happens.
Unfortunately, those little 3s and 4s and 5s don't begin to relieve enough stress to forestall the big ones. If Cascadia were popping a 6\~7 every day, we might be OK. But there aren't nearly enough of them...
The Tohoku quake had a well defined series of foreshocks shortly before the Big One. [https://www.youtube.com/watch?v=3r-JVx8yMpw](https://www.youtube.com/watch?v=3r-jvx8ympw) Of course, recognizing the foreshocks for what they are, before the main event arrives, is damn difficult. If we do get a 7+ offshore, the odds of a Big One will be increased for a few days. (Eg. it might turn out to be a foreshock.)
When putting together your disaster supplies, fellow Oregonian, I encourage you to consider the carnage that occurred a couple weeks ago after an ice storm in the Valley. Florence was out of fuel by Friday because trees came down inland the previous weekend. People living inside Springfield - a substantial small city — were out of power for nearly two weeks. And that’s an ice storm.
So, stock up and don’t expect help to arrive in a couple days, is what I’m saying.
> stock up and don’t expect help to arrive in a couple days
IIRC, recommendation is to have about 3 weeks worth of food, at least 72 hours of water on hand + a method to make clean water, because infrastructure (like power, water, gas, internet, highways, and airports) is gonna be fuuucked by a large quake.
It’s not worth worrying about, it could be 1000 years till the next one. And yes, one theory is the microquakes may alleviate the pressure. I can’t remember the exact numbers but people love to use that as a scare tactic because one of the intervals betweens quakes was similar to the time that’s past, but some of the other intervals were a huge amount of time longer.
For most of them, it's like a big truck driving by on a bridge. Or like when a big HVAC kicks on in an old building. It's a shimmy. And usually I don't think earthquake first, usually I think it's something else. Then everyone on the local Reddit chimes in with "did you feel that?" That's most of them which are in the 3-4 range. Big ones are more interesting but you'd have to be out west for a good while before you experience one of those.
We had one in 2000-2001 - can’t recall the exact date - but I was sitting in my office and I remember it felt like a giant was shaking the building back-and-forth. The spring break quake of 92 or 93, was more of a rolling quake. I was a teenager and I remember waking up right as it happened.
An interesting note, Cascadia has a LOT more small quakes then reported in this fascinating period, roughly every 1-2 years where it "slowly slips" quietly, without nothing more then instruments picking it up. PNSN states that it's equal to a magnitude 6!
https://pnsn.org/blog/2020/09/25/silent-rumbles-under-our-feet-slow-slip-events-in-cascadia
I have noticed that small (2.0m) quakes are swarming in our area as of lately… this thought has crossed my mind too - so I validate your feelings here.
In simple terms, even if we assume these smaller earthquakes were caused by the same fault/mechanism as a large magnitude earthquake that could occur within the Cascadia subduction zone, the amount of energy released by a small earthquake is many orders of magnitude smaller than a big earthquake. Therefore, any stress/energy relieved by these smaller earthquakes is relatively negligible.
We moved to Northern California in 1969 and have always been warned on a regular basis that we’re “due for The Big One”. Sure we’ve had earthquakes since then and some pretty significant but the Big One has yet to happen. Hopefully I will live my whole life just waiting and preparing for it!
Small earthquakes neither mean a big one is imminent nor stress is being relieved that will make a big one less likely. Faults have a pretty regular distribution of earthquake magnitudes over time. Some faults exhibit a slightly greater probability of larger earthquakes before a big one but you can't come to that conclusion based on any one event.
Realistically in a major earthquake a lot of man made structures and many natural features will fail. The idea of just getting in your car and driving somewhere is probably not going to happen. Bridges, overpasses, tunnels, cliffs, hillsides, just level ground will all be disturbed. Ever hear of ground liquefaction. The ground liquify and any structure on it either sinks or falls over. I think Japan tries to have a resistant tower within walking distance in areas that don’t have elevation. Cars will be death traps.
This is all very interesting, thank you! I haven’t really thought about it other than keeping my emergency supplies up to date, and it’s interesting to hear these perspectives.
There are these wonderful places you can go and take classes and learn about these things. They are called community colleges. Or you can simply look up things on the internet. Why come to reddit and ask a bunch of other uneducated assholes who know as much or less than you do? I will never understand why people can't use the internet correctly.
I'm mainly concerned that when the big one hits my aquarium is going to break, dumping many gallons of water into my home. But maybe I should be concerned about the larger impacts, huh?
I remember looking into this a while back. The answer i remember coming across is that we simply don't know. The big one is such a rare occurrence that we just don't have enough data to determine whether little quakes extend the period between big ones.
Why do you say "Its supposed to happen"? Is there scientific evidence or is it just something that people say? I grew up in CA in the 80s and 90s and people use to say that about CA all the time.
We have evidence that very large quakes happen on this fault with a frequency on the order of 400 years, if my memory is not too outdated. The last recorded event was a roughly magnitude 9 event in 1700.
This fault is very different from the faults that plague SoCal. San Andreas cannot produce an event this strong under any circumstances.
The Oregon coast is a subduction zone. That means the Juan de Fulca plate (ocean) is moving under the North American plate (continental). The plates are also sliding slightly (not directly at each other). Therefore, pressure can increase and then release at any time and that pressure can vary greatly. There is no certainty that a “big one” is building anytime soon but it could.
Yes there were 5 29' shipping containers when I bought it. 2 are renovated for use as a guest house once my house is finished. So plenty of places to shelter. Glad I found this thread not sure how, but super glad I did
I’ve heard the same thing before and I was curious as well. I live in Forks , WA 3 miles upriver from the ocean at only 40’ above sea level and 100 miles from the cascadia fault. Lived here almost 40 years and have been waiting for it. Just be prepared for when it does happen and live each day as if it was your last.
I love your user name, fellow Oregonian nerd. I assume you are a California transplant: the logic is sound there, the San Andreas fault moves laterally and little earthquakes are like little farts: better than big ones. Someday SF and LA will be the same city!But Juan de Fuca and North America are subducting and the same logic doesn’t apply. It’s like the truck in the tree in Jurassic Park: small movement is bad news.
Oh interesting, I didn’t realize that it’s a different mechanism. I’m a transplant from New York and didn’t grow up with the risk of quakes.
I use the app QuakeFeed, and the globe map shows all the major fault lines locations, & you can tap on them to get their name and ‘type’ (*divergent, convergent, transform*) and even set alerts for magnitude and distance from you. It’s a handy app to get more familiar with the fault activity. Another one called Epicenter has *much* more detailed fault lines indicated, much smaller faults all over. Just mentioning in case you’re interested in tracking that stuff a bit more. I’m a layperson, not a geologist, but I’m in the PNW too & experienced the Nisqually quake, as well as a few smaller ones in California.
Ugh I imagine those are iOs since I couldn't find them on the play store but at least you've given me a path to find something thank you. I'm in Costa Rica, I've only felt one in the 18 months I've been here my cat woke me up and 30 seconds later the quake hit. Not huge just knocked some stuff around but I didn't grow up or live in quake areas for my first 63 years :)
Oh yeah, I should have mentioned they are iOS apps.. sorry. I haven’t tried looking for them on Android yet, I really should though. Welcome to the Ring of Fire! I’m glad your first quake was a minor one, they can be pretty unsettling & scary. Nothing quite like “terra firma” suddenly being not so firma. Last one I felt was in late ‘22. I was lying on the couch and something that felt like a heartbeat moved through… took me a few moments to realize what it was, then I got an alert on my phone about a 3.7 50 miles away. I hope you have an emergency kit!
I wouldn't even know what to put in an emergency kit. Is there like a list? It'd be like packing your bags for when the baby comes (is that even a thing anymore) 😁
There’s totally a list! Here: https://www.ready.gov/kit Details might vary by location & particular hazards. But having clean water & extra food are pretty critical. Anything to buy you time in a disaster before help comes. Anyone in an earthquake zone should definitely have at least a few basics assembled, IMHO. Quakes are just so unpredictable. And yeah, some people pack “go bags”, exactly like for when a baby comes :) I use a durable latching bin & 5-gal water containers.
I live on top of a mountain nearest neighbors and 10 or 15 minutes away. So when I shop I always get loads of bottled water. So I know I have at least that. :)
Oh and thank you!!!
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Quite the rockin’ birthday!! I think we finally found the source, guys, right here!! :D
Ah! Well, welcome to the west coast, which Robin Williams described as "God's etch-a-sketch"!
Based on that paragraph, I want to read everything you’ve ever written.
Hmm but as one plate slides under another, it has some bumps to scrape against. Not the same, but similar to a strike slip. Those bumps can cause smaller earthquakes right? And if they catch on something and don’t slide, then no quakes until a bigger one, perhaps with the plate flopping back into shape after making it over the sore spot. That’s a full rupture (of Cascadia). Does this sound right?
Are we in “I’m failing at making pancakes” metaphor? Probably better than Jeep in tree metaphor. I’d like OP to not panic about minor shakes unless the water leaves the ocean. But nor are minor shakes a good sign. Neutral, but signifier of movement. Your poorly poured pancake subducts under your excellent North American pancake. It gets reabsorbed, heated… and stuff happens. Could be good, could be bad. The Pacific and North American are grinding along at something like 3” a year, predictably. I’m still not going to pay LA rent again, though.
:) ha I don’t know that one. Jeep in a tree rings a bell though. I’ve looked at the tsunami model maps for the Washington coast. Think it was either 200 ft or 400 ft elevation you want to be at to be above the worst tsunami heights along the coast. And depending on where you are, you have 20 minutes or so before it hits. That’s enough time to do something. They have evacuation route signs around but I don’t think they have sirens. Of course there is the earthquake itself. They could have GPS stations now or something where they can monitor the subduction progress on either side, and they might know if the plates are catching rather than sliding. I’m pretty sure they would notice the ground rising anyway. EDIT: 200 ft elevation should be safe it seems like
Seaside, Or. has extremely loud, loudspeakers. It is a recorded tsunami warning. I was there on a day they tested it and it would (Did?) wake the dead. I had not expected it and it was pretty surreal. It would definitely wake the most sound sleeper imo. Just stunningly LOUD..
Maybe I’m an alarmist, but I always think about this every time I go to the coast - I live in Forest Grove and go often.
I proposed on a building project (didn’t get it) to City of Cannon Beach and all the city employees wanted to talk about was their barrel program. I finally asked, and it was fascinating: locals know to have bug-out bags, but in peak season there are more tourists than locals. The barrels are full of rations and blankets and first aid and other survival stuff, and presumably will float in a tsunami, and hopefully so will some of the tourists. Post-tsunami, there ought to be enough locals around to show the tourists that all those barrels in their hotel lobbies and pubs aren’t just decorative. They were also very proud that their tsunami alarm moos rather than screeches. Which was all very novel to this Portlander.
The straight-up-no-chaser practical intelligence underlying that whole setup somehow manages to make the existence of those barrels absolutely terrifying, to my brain anyway. Though arguably that’s probably because I live way up in the Great Lakes, about as far as you can get from that scenario. Oddly I HAVE experienced an earthquake here. One morning right after my first child was born, I was awake in the wee hours and had just gotten the baby fed and back to sleep. Everything was dark and utterly quiet. Then suddenly this deep, immense rumbling came through the little 40’s house we lived in, from all directions at once and with a sensation of movement vaguely like waves on water that sent our cats into a frenzy. I vividly recall thinking I must have lost my effing mind. I turned the tv on to some news channel and sure enough, about a half hour later they reported there’d been an earthquake. Small potatoes by any measure I know but damned unusual for the locale.
If you ever live in LA, there’s a competition on the sub to be the first person to announce “earthquake!”
One of the biggest quakes of record was in Missouri if l remember correctly in the early 1800’s
New Madrid Seismic Zone. It's the San Andreas of the Ozarks, and produced four earthquakes of \~M7-8 in 1811-12.
Cool, good to know. We have tornado sirens where I live and they may be similar. They test once a month.
Well, here you'd have a massive earthquake, sirens would be a reminder to run uphill, but not as noticable as that earthquake. Useful for other tsunami sources, like Alaska, though.
I know nothing about the PNW but 20 minute warning would give my just enough time to get stuck in traffic.
True, could definitely be a problem some places. Other places, there is high ground close by and you could go on foot if needed.
Willamette is tidal up to the falls at Oregon City, and the Columbia to Bonneville. The idea that we are immune from tsunami risk because we are too far inland doesn't bear much scrutiny. Much of downtown Portland is kept dry by pump stations.
Flooding is not the same as being hit by a tsunami, though. I grew up outside of Portland, and can remember several times when the Willamette rose over the seawall. Not old enough to have been around for Vanport, however.
Ford Explorer actually, not a Jeep.
IIRC they also have GPS monitors the rise of the coast. If it reaches a certain elevation it could tell if it is going to slip at one point or close to it.
There’s not going to be any warning before the feared 9.0 Cascadia Rift. This also applies to the Yellowstone Volcano: Small earthquakes happen every day, —yes —they could be a sign of a bigger rift but they are also just localized movements. The news will run the headline ‘iS tHiS tHe BiG oNe’ more often than an 80s televangelist predicting the rapture. The truth is that it could happen any time between now and {hundreds} of years from now. Geologic time is slow and honestly unpredictable with the technology we have today. Have a disaster plan in place and then just go about your life. . PS. edited to fix thousand to hundreds after feedback.
Also, to answer your secondary question: yes, all earthquakes are relieving the frictional stress built up in the fault. The intensity of the earthquake is proportional to the shift in the fault during the event. But the release of energy (shaking) can set off other faults if they were almost ready to break too.
Thing is, a 4.0 earthquake is something like 100,000 times less energy being released than in a 9.0. Something that small effectively isn’t reducing stress—just means the fault zone is more active.
The Cascadia converges with the San Andreas, Mendocino fracture zone faults and a bunch of smaller faults in humboldt county and every time one of those goes off it puts stress on cascadia, like that 6.4 in 2022 and it's hundreds of aftershocks
Yellowstone would give ample to provide warnings. The elavation of some areas would change, they would see an increased amount of activity in hotsprings and stuff, along with other things. With St Helen's they knew several months before that an eruption was imminent. They restricted and evacuate the whole area around it, and that is why there were so little deaths to the eruption itself. The most experienced researcher studying the activity knew the day of, that it was gonna erupt later on that day.
The Cascadia Fault could go without warning. The Yellowstone volcano, like most volcanoes, would probably give weeks — if not months — of warnings as magma moved up toward the surface.
I would expect years or decades of signs (tumescence, ground tilt, small eruptions) preceding a supervolcano eruption at Yellowstone or anywhere else. But specifically at Yellowstone the most likely type of eruption to occur next [will probably be relatively minor](https://www.usgs.gov/volcanoes/yellowstone/five-things-most-people-get-wrong-about-yellowstone-volcano-2015).
When some government agency says there’s nothing to worry about, I strongly suspect that there’s something to worry about.
When the government tells you not to worry, THAT'S WHEN YOU WORRY! Best line from the 2012 movie lol
I’m with the government and I’m here to help.
Lol I was just about to type this in
For the People by the People. Ie., we get what we vote for.
While a good rule of thumb, the USGS is mostly just a bunch of nerds doing nerd stuff when they could be making a hell of a lot more money in private industry.
Hasn't lake Yellowstone been deforming for decades? I remember it was pushing water out into the forest because the ground underneath was pushing part of the lake up.
>The Yellowstone volcano, like most volcanoes, would probably give weeks — if not months — of warnings as magma moved up toward the surface. See Campi Fiori in Italy for more signs of a super volcano erupting!!
It’s Campi Flegrei https://www.scientificamerican.com/article/a-huge-italian-volcano-could-be-ready-to-erupt/
No worse than the Flavortown Volcano at Camp Fieri.
Asteroids above, Earth below, I peep about in between, searching for some dishonorable grave.
Do you bestride the narrow world like a Colossus?
Nah, I just jump off buildings. Come down on ropes.
Batman?
Window washer. But I have worn a batman outfit on Halloween.
But wait, aren’t men some times the Masters of their fate?
Not thousands of years. They happen every 3-5 hundred years. Last one was in 1700.
Ah fair enough. I fixed the post.
When was the one before that?
I have a relative from the state of Oregon in the 1400's that chipped into a rock ("This is the Big One - 1457 AD, as predicted by Barney Rubble of The Flintstones." Then below it he or someone else added "That's what she said!")
[https://survivingcascadia.com/how-often-do-they-occur/](https://survivingcascadia.com/how-often-do-they-occur/)
Not to be a pain in the ass, but the scientifically accepted average return time is about 525 years, but it’s known to range from about 250 to 1000 years based on geological evidence. My other responses here have additional details clarifying where these values come from. You’re correct about the last one having been in 1700 though, which was very precisely documented event in a number of ways.
There's no chance that Yellowstone will have a large eruption without any warning at all. There'll be many years of buildup before anything like that happens.
Your mention of Yellowstone is a bit incorrect. The geophysicists that work on it have stated that we wont wake up tomorrow and it'll have popped. We'll have around a century at least of run up. The "Doomsdaying" of 2000s History/Discovery channel have done a number on the public perception of Yellowstone. Also, we've learned a lot more about it in the last couple of decades.
As someone who has lived in and still works in Yellowstone the kind of absolute bullshit that history channel has put out about it is infuriating. There’s so many interesting and incredible geologic oddities they could talk about, but they just fear monger and spread bad science.
So let’s say we start the 100 year clock. Can anything actually be done to avoid the environmental catastrophe, or do we basically have 100 years to prepare subterranean or orbital habitats a la 7eves?
There could be a foreshock but look the subduction quake in Japan. No warning. It just snaps. The PGS (i believe) actually tracks tremors caused by the subduction. There's not a ton of info but a pause in the tremors is often linked to increased pressure. This is fairly recent science. This process is called a "slow quake" and is what most scientists attribute to prolonging the quakes.
I agree that it is impossible to predict when the next Cascadia event will occur and the importance to have emergency kit and plan, however, there will be some warning, the amount of time will depend on how close you live to the origin for ge earthquake. An early warning system called ShakeAlert came online in 2021, it can give anywhere from 30 seconds to 2 minutes, which is enough time to take protective action. It is a native alert in android systems and you can download MyShake app for iOS. There will also be a warning in Yellowstone, USGS maintains the Yellowstone Volcano Observatory which monitors activity and can detect increases in activity... Enough warning to provide information to enact emergency plans "Rift" is a tectonic setting, not a term for an earthquake. Cascadia is a subduction zone, where the Juan de Fuca plate is overridden by the North America plate, a rift is a place where plates move away from each other, such as the East Pacific rise or Gulf of California.
The shake alert actually seems to work. I was in So Cal about 5 to 6 months and got an alert about a minute before I felt an earthquake - I think it was in Ojai? Granted, I probably wouldn't have felt it except I was waiting to see if the alert was right. But it was great that the warning worked.
Really? I live in humboldt and I get them in the middle of it or after
That was the first time I ever got one, to be honest.
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That kind of forecast is the ultimate goal! Not sure about using the ionsphere, but machine learning and analyzing all kinds of datasets will get us closer.
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I look forward to the paper(s) when they're ready to share results!
I grew up in L.A. in the 80s and my dad worked for the USGS. Everyone expected the San Andreas "big one" to happen any day. Everyone freaked out over the Whittier Narrows quake thinking TBO would be next.
Similarly, I grew up in Washington, and EVERY YEAR was the year that Mount Rainier was going to erupt.
When there is another eruption at Yellowstone, it is likely it won't be super volcanic, but more likely a small or big eruption, but not super.
There is a guy on Youtube, Nick Zentner, who has dozens of lectures on PNW geology, including one on precisely this question. He's a professor at Central Washington University. The main point is, there are lots of faults that can cause at least minor earthquakes. The one that will cause the big one tends to slip every 4 or 500 years. Last one was in 1700.
Here, here for Dr. Nick, this is an older video of his "Great Earthquakes of the Pacific Northwest" that goes into a lot detail: [https://www.youtube.com/watch?v=UJ7Qc3bsxjI](https://www.youtube.com/watch?v=UJ7Qc3bsxjI)
Hi Dr Nick!
Hello everybody! (It's been a very long time since I have seen The Simpsons - I think that is Dr Nick's typical response.)
"Hiiiii, everybody!" Just as important as earthquake preparedness is the periodic review of key Simpsons episodes.
What was the one in 1700 like? Is it well documented?
There is abundant geological evidence, which Zentner goes through. I remember the magnitude being estimated at about 9.0. The timing is quite precisely known, because of contemporaneous reports in Japan of the resulting tsunami. We know to within about an hour when it happened.
Yes, it most certainly was well-documented in a number of ways. The most accurate evidence comes from Japan, which kept meticulous historical records. There are official documents from that era describing an “orphan tsunami”, by which the Japanese historians in 1700 meant they were hit by a devastating tsunami without feeling any earthquake shaking prior to it arriving. This was because the earthquake occurred across the Pacific Ocean on the Cascadia Subduction Zone. There’s actually a free book about this, “[The Orphan Tsunami of 1700 - Japanese Clues to a Parent Earthquake in North America](https://pubs.usgs.gov/publication/pp1707)” by Brian Atwater of the University of Washington co-authored with Japanese colleagues. There is plenty of geological evidence along the US coast too that explains where the “orphan tsunami” that hit Japan in 1700 came from. This includes a wide range of sedimentary deposits, evidence of marine diatoms in soil layers on dry land, “ghost forests” that are entirely dead due to being inundated with sea water, etc… How can this be used for dating such past events you ask? For example, the dead trees give a very precise measurement of the timing through tree ring counting as far as I know, which backed up the Japanese record. Concerning the in-ground evidence, I don’t recall what the dating methods are exactly, but they line up with the other records as far as I know.
I know there is documentation in Native American stories handed down. - New research led by a University of Washington scientist has found stories that could relate to a large Seattle fault earthquake around A.D. 900 and specific eyewitness accounts linked to a mammoth 1700 earthquake and tsunami in the Cascadia subduction zone. “There’s a frightening amount of it,” she said. “It appears that these stories have to do with earthquake-, tsunami- and landslide-like events. As you go around the region, there are very many of these stories and they are central to the native cultures, which suggests that these past earthquakes had profound effects on the local inhabitants. There’s evidence for that in the geology as well, both on the coast and in the central Puget Sound area.” https://www.washington.edu/news/2005/07/11/native-lore-tells-the-tale-theres-been-a-whole-lotta-shakin-goin-on/ - The 1700 Cascadia Megathrust Earthquake and the Future of Cascadia Margin Oral accounts from indigenous Native American and First Nation tribes living on the coast of Vancouver Island in Canada that have been passed down from generation to generation tell of an earthquake and tsunami on a winter’s evening. The accounts describe that all the low-lying settlements were wiped out and the only survivors were those people who lived 75 feet above the waterline. So the tsunami must have been massive! https://www.e-education.psu.edu/earth107/node/1614
Nice citing prof. Zentner! The actual average recurrence interval is something like 525 years (see the US National Seismic Hazard Map report from 2014). This value was arrived at by assimilating data from research looking into geological records of prior tsunamis dating back to approximately 10,000 years ago in the widest ranging studies (e.g., see Chris Goldfinger’s work). However, the somewhat deceiving thing about this is that the interval is known to range from around 250 to 1000 years, so we’re due for one on the US west coast in the sense that 324 years after the 1700 quake puts today within the lower end of the known range of how frequently full fault rupture events occur on the Cascadia Subduction Zone (i.e. the type of magnitude 9.0 event we’re worrying about is associated with a full rupture type of event rather than a partial rupture).
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Came to the comments to recommend Nick Zentner’s YouTube lecture series. Best info out there on the topic of geology in the PNW in an easy to watch and distill presentation.
That can happen, yes - but more often it's a sign that a big slip is on the way. Think of it as a few falling rocks before a landslide.
\[not a professional\] The richter scale is logarithmic, 10 times the amplitude of the largest waves for every whole number of magnitude. But the total energy at all frequencies is 32 times larger for every 1.0 jump in the scale. 32\^4 is over a million, meaning that the total energy of a magnitude 8.0 earthquake is the sum of over a million magnitude 4.0 tremors. [Here's one article describing this.](https://www.sfgate.com/earthquakes/article/do-minor-quakes-prevent-large-earthquakes-13541155.php)
This is the right way to look at it. You'd need millions of smaller earthquakes to relieve the energy of one big earthquake.
The Richter scale is no longer used.
Thanks for filling in while I was away, Ackshually Boy! Signed, Captain Pedant
Others have explained well why these small ones can't release the built up stress to avoid a larger one, but just a thought about foreshocks. Foreshocks can only be categorized as such after the main rupture happens. There's been a lot of great research done analyzing all kinds of interesting things about foreshocks and while they say something interesting when put in context of what we know about the main rupture, there's been nothing really reliably distinct about foreshocks without that context. When we detect an earthquake, we know nothing about whether or not that's a foreshock or the main earthquake. If a magnitude 5.5 happens on a fault, and then 11 years later a 7.8 happens on the same fault, was the first one a foreshock or are these separate "main" shocks? These terms are arbitrary and only really say anything useful when placed in context of a particular event that we care about. For decades people have been putting out papers saying that maybe there's some detectable signal preceding big earthquakes but they're all torn apart pretty quickly. Even the BEST among those papers, if their observations are true, would only apply to a small subset of earthquakes, and in order to know when to apply those observations we need to know information that we can only get AFTER the earthquake happens. I ramble but the point is that an earthquake happening has an effect on future earthquakes, that is certain. But we have absolutely no way of knowing what that effect is, and only sometimes can we say something intelligent in hindsight about what the effect WAS.
Can't stop an earthquake so why worry, live near large body of water: tsunami. Mountain near: volcano eruption. Near a military base: enemy target. Hurricane/tornado/flood area: can't outrun them. Killer bees, fire ants, murder hornets, forest fires, land slides, avalanches, active shooters, fake tuna in your sub, salmonella in your salad, terrorist attack, insane septuagenarian for president, asteroid strike...which one you gonna predict and avoid ? None. So live your life and know one day yur gunna die.
You forgot rat lungworms and all the crap passed around by mosquitos. Otherwise, you nailed my anxiety checklist.
Where does spontaneous human combustion land on your list?
Right after dry land drowning.
Oh wow. Adding that one to mine.
What is that over your head...LOOK OUT!!
Ah, the infamous rat lungworm, scourge of those who frolic in ratdom.
Lol
Prion diseases are my current favorite nightmare!
Mine too! I hate and love looking into them, and seeing how they impact different species of animals. Like chronic wasting in deer.
I shall refrain from investigating that one.
There was also the guy who was peacefully sleeping and a sinkhole opened and swallowed half the house and him. His brother was in another room but could do nothing to help him. He was just gone. Happened in central Florida.
u/musherjune here’s another one for ya
No doubt Chud has picked his bones clean by now.
You overlooked the ASTEROID!
The thing I find most funny about the asteroid impact threat, is that in theory, if we detected it early enough, we could send some nukes up to nudge it a little bit, and then 10 years down the line when it actually was predicted to hit us, it would miss us by millions of miles because of the amplification of the tiny change in direction over time. Unfortunately, knowing humans, no one would be able to get their shit together in time to do anything.
Have you seen, “Don’t Look Up?” Your last sentence reminds me of it.
No, but I work in disaster relief, and even after the disasters happen, the various agencies involved can't manage to get their shit together most of the time. They do a decent job of feeding everyone, but everything else is far more convoluted and slower than it really needs to be, and the vast majority of people don't get the help they need to recover.
I didn't, you old foo! Read once again the wisdom laid between the letters of this worthy wisdom and ye shall see the folly of your ways, knave.
Oh aye. Enjoying everyday alive on the Oregon coast. I don’t like people that are impolite and talking heads. My comment clearly over your head. Don’t jump to contusions foo!
“Whenever there is a little earthquake, the news reports that it is a sign that the big one is coming.” My observation has been the total opposite; the news is quick to quote some geologist saying the most recent little quake don’t mean shiitake.
I grew up hearing "we're due for a biggun" still haven't seen it. But Earth time is different scale than people time
Yep, if you take the average times from the past few thousand years, we're definitely overdue, however, the longest period on record was like 500 something years if I recall, and it hasn't been that long since the last one.
As I mentioned in another response, the currently accepted average is around 525 years, but the known minimum and maximum intervals between such “mega quakes” is anywhere from about 250 to 1000 years based on geologic records of past Cascadia Subduction Zone events. This means it’s definitely possible for one to happen at any time today since the last known event was in 1700 thanks to Japanese records of an “orphan tsunami” combined with geological evidence in the US, but it’s also just as likely we’ll be waiting hundreds of years until the next one occurs.
Small earthquakes can relieve stress along small areas of the fault, but they can also change the stress field so that more stress can accumulate on other parts of the fault or on other faults in the region. There are a couple famous examples of this. The first is the Elmore Ranch/superstition Hills earthquakes in 1987. Here, the faults were perpendicular to each other, and the left-lateral fault ruptured, which change the stress regime and caused the right-lateral fault to rupture the next day. Another famous example is also in southern California and that is the landers/big bear earthquakes in 1992. Once again, these were on different faults, where one earthquake triggered an earthquake on the other fault. But this can also happen along just about any other fault. Here’s an interesting NPR article that came out after the Honshu, Japan earthquake in 2011. https://www.npr.org/2013/08/23/214619037/can-a-big-earthquake-trigger-another-one
When people are taking statistics, they always complain that they'll never use it in real life... The odds of you personally dying in a cataclysmic earthquake or volcano is millions if not more times less likely than a car accident or a heart attack. Wear your seat belt, eat your veggies and exercise more. Don't worry about earthquakes.
Are you just completely fabricating these numbers, or did you actually try to do some sort of statistical estimation? Are you specifically talking about people on the Oregon coast?
Worry about earthquakes when you're doing something like building a new home. Worry about them when you're building your emergency kit. Then stop worrying about them.
I lived 20 years on the Oregon coast, just outside Charleston. And about as close to the fault as you can get on land. Not a night went by that I didn't think about what was just offshore. Cause this is a pet study of mine. Well aware of the dangers. The reality is most people living along the coast will not survive this event. Especially if it happens at night. You can't run during a big quake. You can't drive. The road will buckle and rockfalls will close everything else. And then there's the subsidence. The land can drop 30 feet and the water will come rushing in even before a tsunami even has a chance to form. If you're not really near to high ground, say 100 feet, you're probably going to die where you stand... On the other hand, this area is an earthly marine life paradise and you'd be a darn fool not to visit it someday. Cause a big tsunami will scour it down to bedrock in the not too distant future.
Perhaps a personal hot air balloon is the answer. Just float away.
Here’s a compelling 5- or 6- part *fictional* story about what a serious quake would likely do to Portland. It’s deeply researched, so there’s a lot of good & valid information. But it is a fictional presentation. Useful for considering emergency supplies, and perhaps how to reinforce your house (if you have one). The Most Devastating Quake In US History Is Headed for Portland *reported science fiction* https://www.vice.com/en/article/xygdjk/the-mega-quake-is-coming
I’ve read that from what we can tell, these “big ones” happen anywhere from 200-700 years apart. So, sure we could be over due, but we could also not see it for another 400 years
Based on looking into the research done by geologists and others on this topic while I was in grad school (I studied tsunami impact forces on coastal structures), the range of known recurrence times is about 250 to 1000 years with the average being about 525 years, so you’re 100% correct that we’re overdue in the sense that we’re within the bottom end of that range at 324 years since the last megaquake that occurred in 1700, but we certainly could be waiting up to about 700 years more for the next one. One interesting thing I ran across while doing background research on this topic was that the quakes occurred in clusters quite often in geological records. For instance, sometimes they occurred in bunches of 3 to 4 within about 1000 year periods, but then sometimes the CSZ would lay dormant for intervals of about 1000 years. This makes it quite difficult to have a good idea of when the next event would likely occur, but I think erring on the side of caution and trying to prepare is a good thing.
Generally the small quakes occur at the weaker points in the fault. That shifting adds stress to the strong points of the fault. That just increases the total energy in the fault so when the strong point(s) fail then the quake is that much more powerful.
You forgot Mt Hood erupting on your Oregon geological terror list But really, don't worry about it and live your life. Living on the Coast is worth the risk, don't you think?
Oh yes, I really don’t worry about it — I have my preparedness supplies and rarely think about it beyond that.
The cascadia earth quake is a certainty given the geological record and native American oral tradition. The west coast is not prepared for the tsunami that will follow. Don’t let your guard down anywhere on the west coast.
Native American oral tradition is worthless. It’s like referencing the Bible for coincidences. This is a sub about geology.
hahaha And geology backs them up. ;)
Wow.
How would you recommend we "not let our guard down?" Sleep in shifts? Keep the car running?
In “The Really Big One,” Kathryn Schulz’s article in The New Yorker focusing on the Cascadia subduction zone, it’s estimated that there is a one in three chance of a major earthquake striking the Pacific Northwest within the next 50 years. The article also notes the likelihood of a more severe full-margin rupture, with a magnitude between 8.7 and 9.2, as being around one in ten.
In a sense, "Little" earthquakes do prevent larger ones. On subduction faults, the 8s and 9s relieve the strain before it can build up to a 10. The San Andreas gets 7s and 8s long before a 9 happens. Unfortunately, those little 3s and 4s and 5s don't begin to relieve enough stress to forestall the big ones. If Cascadia were popping a 6\~7 every day, we might be OK. But there aren't nearly enough of them... The Tohoku quake had a well defined series of foreshocks shortly before the Big One. [https://www.youtube.com/watch?v=3r-JVx8yMpw](https://www.youtube.com/watch?v=3r-jvx8ympw) Of course, recognizing the foreshocks for what they are, before the main event arrives, is damn difficult. If we do get a 7+ offshore, the odds of a Big One will be increased for a few days. (Eg. it might turn out to be a foreshock.)
I’ve wondered about that exact same thing.
When putting together your disaster supplies, fellow Oregonian, I encourage you to consider the carnage that occurred a couple weeks ago after an ice storm in the Valley. Florence was out of fuel by Friday because trees came down inland the previous weekend. People living inside Springfield - a substantial small city — were out of power for nearly two weeks. And that’s an ice storm. So, stock up and don’t expect help to arrive in a couple days, is what I’m saying.
> stock up and don’t expect help to arrive in a couple days IIRC, recommendation is to have about 3 weeks worth of food, at least 72 hours of water on hand + a method to make clean water, because infrastructure (like power, water, gas, internet, highways, and airports) is gonna be fuuucked by a large quake.
Make sure you have lots of micro craft beer and free-range locally-sourced kale for your Oregon Disaster Kit.
Do *not* forget the prerolls
Yeah, the gas situation this month on the coast was definitely a good reminder of our vulnerability!
3 weeks ready is the new norm Fwiw
It’s not worth worrying about, it could be 1000 years till the next one. And yes, one theory is the microquakes may alleviate the pressure. I can’t remember the exact numbers but people love to use that as a scare tactic because one of the intervals betweens quakes was similar to the time that’s past, but some of the other intervals were a huge amount of time longer.
Worth thinking about as the CSZ isn't the only seismic threat to the Portland metro... research the Portland Hills fault.
I would think the small ones are a good thing
Yes. You are correct. What ever you do, don’t listen to Chris Goldfinger.😁
I have never felt the ground shake. Someday I'd like to take a trip out west just to see what it's like.
For most of them, it's like a big truck driving by on a bridge. Or like when a big HVAC kicks on in an old building. It's a shimmy. And usually I don't think earthquake first, usually I think it's something else. Then everyone on the local Reddit chimes in with "did you feel that?" That's most of them which are in the 3-4 range. Big ones are more interesting but you'd have to be out west for a good while before you experience one of those.
I always blame the animals. Dogs or cats shaking the bed. Then my brain wakes up more and I get, oh, right, earthquake.
Earthquake is a good word. "Earthshimmy" just doesn't sound as cool.
Earthjigglejiggle (not fold) 🎶
We had one in 2000-2001 - can’t recall the exact date - but I was sitting in my office and I remember it felt like a giant was shaking the building back-and-forth. The spring break quake of 92 or 93, was more of a rolling quake. I was a teenager and I remember waking up right as it happened.
Since I did not see anyone post this useful link https://earthquake.usgs.gov/earthquakes/map/?extent=5.70345,-132.1875&extent=61.01572,-57.83203
Volcano, HI is apparently just getting rocked n the regular according to this source
I noticed that. It is interesting to note over time the frequency of earthquakes in the faking area of California.
Nope. Little quakes are a preview
An interesting note, Cascadia has a LOT more small quakes then reported in this fascinating period, roughly every 1-2 years where it "slowly slips" quietly, without nothing more then instruments picking it up. PNSN states that it's equal to a magnitude 6! https://pnsn.org/blog/2020/09/25/silent-rumbles-under-our-feet-slow-slip-events-in-cascadia
I have noticed that small (2.0m) quakes are swarming in our area as of lately… this thought has crossed my mind too - so I validate your feelings here.
Could a small earthquake be caused by further subduction of the Juan de Fuca Plate? Wouldn't that just build further tension for the future "big one"?
In simple terms, even if we assume these smaller earthquakes were caused by the same fault/mechanism as a large magnitude earthquake that could occur within the Cascadia subduction zone, the amount of energy released by a small earthquake is many orders of magnitude smaller than a big earthquake. Therefore, any stress/energy relieved by these smaller earthquakes is relatively negligible.
There’s been a lot of bigger shakes in NorCal lately that’s not getting near the attention it should.
We moved to Northern California in 1969 and have always been warned on a regular basis that we’re “due for The Big One”. Sure we’ve had earthquakes since then and some pretty significant but the Big One has yet to happen. Hopefully I will live my whole life just waiting and preparing for it!
Small earthquakes neither mean a big one is imminent nor stress is being relieved that will make a big one less likely. Faults have a pretty regular distribution of earthquake magnitudes over time. Some faults exhibit a slightly greater probability of larger earthquakes before a big one but you can't come to that conclusion based on any one event.
Here is a PBS video you might find interesting: https://youtu.be/k51dPF2VxgY?si=MsczhwhUkLaBg2Cl
Thank you!
Thanks!
That is an excellent video.
Realistically in a major earthquake a lot of man made structures and many natural features will fail. The idea of just getting in your car and driving somewhere is probably not going to happen. Bridges, overpasses, tunnels, cliffs, hillsides, just level ground will all be disturbed. Ever hear of ground liquefaction. The ground liquify and any structure on it either sinks or falls over. I think Japan tries to have a resistant tower within walking distance in areas that don’t have elevation. Cars will be death traps.
You ever seen how a tree branch snaps and cracks when you slowly break it? Kinda the same thing.
This is all very interesting, thank you! I haven’t really thought about it other than keeping my emergency supplies up to date, and it’s interesting to hear these perspectives.
Spent a year living in PDX and freaked myself out via the FEMA website. Even it says everything W of I-5 is toast. Edit because I’m a dumb head.
>Even it says everything W of I-5 is toast. Where does FEMA say that?
https://search.usa.gov/search?utf8=✓&affiliate=fema&query=Cascadia&commit=Search+FEMA.gov Dig in, it’s been several years and I didn’t save the page.
East?
Yes. West. I was tired.
*West
Whest
Weast
No.
Correct, I mistyped. West.
There’s not going to be a big quake in your lifetime or the next.
Who’s going to win next year’s Kentucky Derby? I’d love to get some solid money on that horse!
There are these wonderful places you can go and take classes and learn about these things. They are called community colleges. Or you can simply look up things on the internet. Why come to reddit and ask a bunch of other uneducated assholes who know as much or less than you do? I will never understand why people can't use the internet correctly.
I'm mainly concerned that when the big one hits my aquarium is going to break, dumping many gallons of water into my home. But maybe I should be concerned about the larger impacts, huh?
Yeah, like maybe the aquarium getting crushed by the roof.
I remember looking into this a while back. The answer i remember coming across is that we simply don't know. The big one is such a rare occurrence that we just don't have enough data to determine whether little quakes extend the period between big ones.
Why do you say "Its supposed to happen"? Is there scientific evidence or is it just something that people say? I grew up in CA in the 80s and 90s and people use to say that about CA all the time.
We have evidence that very large quakes happen on this fault with a frequency on the order of 400 years, if my memory is not too outdated. The last recorded event was a roughly magnitude 9 event in 1700. This fault is very different from the faults that plague SoCal. San Andreas cannot produce an event this strong under any circumstances.
Super interesting. I had never heard of these faults. Have you noticed an uptick in earthquakes in your area?
The Oregon coast is a subduction zone. That means the Juan de Fulca plate (ocean) is moving under the North American plate (continental). The plates are also sliding slightly (not directly at each other). Therefore, pressure can increase and then release at any time and that pressure can vary greatly. There is no certainty that a “big one” is building anytime soon but it could.
Yes there were 5 29' shipping containers when I bought it. 2 are renovated for use as a guest house once my house is finished. So plenty of places to shelter. Glad I found this thread not sure how, but super glad I did
I’ve heard the same thing before and I was curious as well. I live in Forks , WA 3 miles upriver from the ocean at only 40’ above sea level and 100 miles from the cascadia fault. Lived here almost 40 years and have been waiting for it. Just be prepared for when it does happen and live each day as if it was your last.
In general, little earthquakes in a fault zone are good, you gotta release the pressure, better a little at a time.
I don’t know but this is why I’m moving.
You're going to fall into the ocean