Cascadia: The Earthquake that will Destroy Westcoast America 

My step mother’s father was a geologist who was a member of one of the teams that put together the risk analysis for a potential Cascadia subduction zone quake. The historical record uncovered and the implications for present day danger were so alarming that he not only left the Pacific Northwest, he moved to Europe and never came back.

I love how Simon covered this with the enthusiasm of someone who clearly doesn't live in the Pacific Northwest

I lived in Anchorage when was 7 years old and the 1964 Good Friday earthquake hit. Although there were no earthquake meters at the time, I've seen estimates of it being anywhere between a 9.2 t0 9.5 earthquake. It was terrifying. To this day, I (and anyone else I've met who lived through it) cannot speak of it without crying. I was in Seattle during the 6.8 Nisqually earthquake in 2001. It was nothing compared to the Good Friday earthquake. At 6.8, the Nisqually earthquake made the ground feel like a gentle rolling wave with the sound of thunder coming from underground. It lasted for less than one minute. The Good Friday earthquake made the ground shift violently back and forth with so much force that everyone standing outside fell to the ground, only to stand back up and then be hurled to the ground in another few seconds. It lasted for 4.5 minutes, but felt like it went on forever. My brother said he was watching the trees, sway so much that the tops of the trees would touch the ground, stand back upright, and then sway in the opposite direction and touch the ground again; over and over. I don't remember sounds besides people screaming and houses sounding like they were pulling apart. As a young girl scout, I remember our troop was on a guided walk in a State forest. The forester pointed out that the trail we were walking was directly over the fault of the Good Friday earthquake. She pointed out a tree that had grown directly over the fault line. The tree, still upright, had been ripped in half with one half located about 15 ft. from the other half. To this day, the memory of that sight is still mind-bending. I recognize the photo of downtown Anchorage shown in the video. My father went into town a few days after the quake and took a movie of Anchorage's streets. We watched those films regularly. My dad was an air force pilot and flew over Valdez on a reconnaissance mission. From the air, he took a movie of the port, the wrecked docks, the large ships sitting atop crushed homes, and washed out roads. We watched that movie regularly, too. As an adult in Seattle, I discovered that my neighbor had lived in a community near Valdez that was not as affected by the tsunami. All of her friends in Valdez perished. Many years later, my mother told us that my father always slept with his boots on for the next year or so after the earthquake. Now living in the Seattle area, I have always made my housing choices based on staying out of tsunami range and knowing the geology of the area I live in (to minimize impacts from earth movement). I do enjoy going out to the coast now and then but must admit a certain nervousness until I get back to safer ground.

My dad is Alaskan and survived the 1964 quake, but lost several friends. He moved to Europe when he was 20 and this was partially motivated by that earthquake he and his family barely survived.

Seattleite here. You missed two things: 1) We DO get earthquakes on a somewhat regular basis that can wake us up or shatter the odd window. 2) A 9.2 will have enough force to loosen the glaciers on Mt Rainier, if not awaken it or one of its brethren. Don't worry, it's worse than you think.

Not gonna lie, I was fully expecting this to be 2020's final boss

One thing everyone forgets in the scenario, is Mt. Rainier. At the very minimum, you will have avalanches coming at you at frightening speeds. If you have deep shaking, it could affect the volcano itself.

I attended a training session about disaster preparedness held near Everett, WA about 20 years ago. One of the local USGS geologists was a presenter. He said we need to have our emergency preps stored well away from buildings and buried (with lid access) to protect them from earthquake damage so we could actually retrieve them when we need them. He said we will need them and our buildings/homes aren't likely to be standing to get our preps from inside. He said our go bags needed to be kept next to the door we will be exiting through. Very chilling to listen to how he, personally, was preparing for such a recently discovered threat. I have been prepping since Mt. St. Helen's blew, myself, so the concept of prepping wasn't new to me. It pretty much was to everyone else there. I live about 15 miles EAST of I-5 and avoid WEST of it like the plague.

One element of my job is to ensure corporate data survivability by backing up data at redundant, geographically seperated data centers. While inspecting one San Francisco firm, we discovered they had no redundant data backup. When I enquired, the VP rolled his eyes at me and said " Ive heard [earthquake] predictions all my life, but other than a small tremor here and there, there hasnt been ANYTHING to worry about!" This is the problem. People have no frame of reference. They think it wont happen because it hasnt yet happened to THEM.

In the early 80s I stayed with someone who had a ranch that the San Andreas fault ran through. Some people showed up from (as I recall) a university. They placed measuring devices into the fault line, then quit for lunch. When they returned they tried to remove one of the devices and they could not get it out of the ground. In about 90 minutes the plate had moved enough to trap some of their equipment. I saw that with my own eyes. They were pretty stimulated about the amount of movement in that short time. The ranch owner is dead and now I’m old, but I sure remember that. It took place in December 1981.

1982, my ship pulled into a harbor on Talcauno, Chile. The harbor bottom was about 50 feet deep. NOW, THERE IS NO HARBOR AND THAT AREA IS NOW NEAR SEA LEVEL.

I currently live in this Cascadia zone. It’s scary how many people don’t take this possibility seriously. I plan to move inland soon and can’t wait as this has been a huge source of anxiety and nightmares for me.

Simon: "The next mega quake is 70 years overdue." 2020: _Sits quitely in the corner taking notes._

As someone who digs subway tunnels in Los Angeles for a living, this is concerning to say the least.

My dad was in college in Oregon when the new cascadia research was being done in the 80s. When it was my turn to go to college in Vancouver BC, moving into those new glass high-rise apartments he said, “You really don’t want to be living here during an earthquake. The whole PNW is almost 100 years overdue for a Big One.” He meant like a 1964 earthquake where we grew up, and personally got a taste of in 2018.

growing up in Mexico city all my life and living thru countless earthquakes, I can guarantee you that this documentary is 100% accurate . great work

I feel like Cascadia and Yellowstone are making plans for a date...

“We don’t expect this will happen again anytime soon”, The CDC describing a more deadly SARS type outbreak in 2014

I live in eastern WA, and when traveling near the coast, I have seen stands of dead trees in certain areas. The trees in these "ghost forests" were analyzed in the 80s and 90s, and they drowned circa 1700, victims of the tsunami. There is a video on youtube made by Central Washington University about these tsunamis, and on the video it says that these tsunamis occur about every 500 years on average.

Has anyone else been binge watching these videos? I’ve been stuck watching/listening to them every day for hours on end, mainly listening to them at work. So addicting.

Chilean here, I just wanted to say that we are lucky to have earthquakes so often (like with 15~20 years of difference), because that way we are forced to have better quality of buildings and houses, most of old houses in Chile can't survive the quakes, so the ones that are standing right now have been proved by the circumstances.

Simon: "It's unlikely it will happen in your lifetime" 2020: "Hold my Corona"

Your information access is amazing. Such a great job. Keep it up my friend.

Can say that I've felt two good ones 3-4 on the scale on Vancouver island, notably my high school English teacher tossed us away from our desks so she could hide under it for us. That was the one that damaged some buildings in Washington state that year some time around 2003. the second one was while I was in college and it felt like some one dropped a fridge on our house, woke up my room mate who said it was like a bell ringing through the basement off the bedrock. You feel em or hear them.

Me living on the san Andrea's fault line poking at it with a stick

"When the big one hits, Nevada will be wine country." - Robin WIlliams

I'm really fascinated by how the scientists collected and studied the oral folklore of Native Americans and used to it essentially triangulate an actual event.

Almost 47 years (since birth) in Western Washington state and I've felt one earthquake in February 2001. You can't really sweat the big stuff.

In Oregon, this earthquake is pounded into our heads via school. They basically tell us "yeah there is an earth quake that's supposed to come every 300 years, but it's late and can come anytime. So let's hope we don't dir

The first rule of living on Cascadia Subduction Zone: DON'T TALK ABOUT CASCADIA SUBDUCTION ZONE!

I live 20mins outside Spokane, Washington and we had a very weak 2.7 tremor the other day. They happen once in a while in Eastern Washington, but usually so weak that we don't feel anything. Just like the one from the other day.

I do appreciate your programming, Simon. Thank you

"some say the fight was between thunderbird and Transformer" I immediately imagined Optimus Prim punching Zaptos in the face.

As a geologist living near San Francisco, both the Cascadia and San Andreas Fault Systems are of great concern to me, not only for major earthquakes but for huge tsunamis. It always fascinates, and dismays, me that surveys of factors considered of importance to potential home buyers, the first priority is “view”, the last priority is “geologic safety”. Even though the most modest “entry level” home starts at about $1.5 million where I live, buyers can’t be bothered to get a geologic report, or even read the ones that have already been done for the specific property. Then when their houses fall down, they go around shouting “why didn’t anyone tell me?!” Nor do very many buy earthquake insurance, it’s really expensive and only pays 75% of the value of the home. I can’t afford it myself.

I lived in Salem area for 20 years. Weirdly, I had nightmares about tsunami and running away from it lol. Finally moved far away to the East cost and haven’t had a single nightmare in 4 years. Something is weird happening there for sure. Living there I had terrible migraines and felt dizzy & sleepy all the time. Unfortunately non of my family believes in it happening and I can’t convince them to move.

I grew up on the coast of Washington just south of Victoria BC. Learning about the "big one" coming absolutely terrified me as a teen. I've now moved eastward to a town just south of Vancouver BC 😅 right on the I5. Still not quite far away enough to be in the clear, but much better odds and definitely on higher ground.

What did the Earth say about the earthquake? “Sorry, It’s my fault.”

I live in Greece, a relatively earthquake-prone country, and I've been laughing at my German mother for being afraid of them. I need to go apologise. Maybe get her some flowers too. Or a hardhat.

Excellent work thank you for your time detail this

I live 10ish miles west of Eugene. We're blocked off from the beach by 750-1,000ft tall hills and are about 500ft in elevation. The tsunami would have to travel 50 miles inland and pass over those hills to reach us, and another 20 miles to interstate 5. The shaking and fires will reduce us to rubble, absolutely, but the Eugene/Springfield area will be dry. We'll have beachfront property in Veneta where I live 😆

Ah so that's what 2020 is getting us for xmas.

"Mostly quiet, but occasionally apocalyptic" 😂

I lived near Seattle for 30 or so years and experienced 2 or 3 quakes that I could both feel and see so you're not quite right there.

Not to downplay the terrible losses of the earthquakes Simon mentioned, I am always amazed at how many docos forget that the 2004 Sumatran earthquake, (also caused by a subduction earthquake) and the tsunamis which followed, killed over 250,000 people.

2020: August: Cascadia Fault earthquake September: Yellowstone supervolcano eruption October: Nuclear war November: Earth gets hit by an asteroid strike December: Aliens attack

as an Oregonian, I wanted to say thank you for pronouncing our state correctly, and curse you for making it impossible to sleep tonight.

I love your Geographics channel, it's one of my favorites. Thanks!

I remember one earthquake. I was babysitting my neighbors chickens and one day after I was there for an hour, they all squated down spreding thier wings down on each side while I grabbed a tree and hung on. Lasted @ 5 minutes but I was thrilled by the experiance. Kudos to the chickens for the warning.

"Ur gonna die and all ur loved ones will fall with you..... Anyways, dont forget to support todays sponsor, Curiosity stream"

As a Californian living in Los Angeles I’m just praying that the earthquake won’t happen while I’m taking a shit

A friend in my university days spent several summers examining coastal deposits in Oregon and found area after area that have been tilted and then falling back level over and over, showing that as the subduction zone pressure builds sections of the crust along the coast tilt from the pressure and then when a big quake hits the slabs of crust drop back to level, which complicates a quake because while the ground is shaking it's also tilting.

Superb analysis and explanation as usual...Your content is both informing and warning to be aware of what may come.

Coming from someone who's lived my entire life in the pacific northwest, you shouldn't live here without an emergency plans for natural disasters earthquakes or not. If it's not an earthquake it'll be a savage wildfire. Either way you don't want to wait until it's happening to figure out what you're gonna do.

"71,000, as many will run to the hills".... I think you forget how absolutely moronic some people in America can be.... We'd rather stand there and take a selfie.

Having grown up in Cascadia, and my family moving there in the early 19th century. (not the subduction zone, but the community of Cascadia in Oregon) I enjoy reading and hearing about anything "Cascadia".

Simon should have used the Beach Boys Surfing USA for background music 😂

I actually worked in the FEMA Cascadia table top exercise. This is where experts in their respective fields estimated the damages, and how quickly emergency crews could respond, also, how long it would take to recover. Everything this video says is exactly what the exercise determined. I was part of the Portland portion. In Portland, the downtown area will be subject to liquifaction. Buildings that are brick will of course, simply fall apart, everything else will sink into what will turn into quicksand. There will be bridges still standing, but the approaches will have been sunk. I-5 will be impassable. The Portland Airport will be unusable as it is also built on soil that is subject to liquefaction. Of course the dams on the Columbia will have failed, meaning flooding and total loss of power from that source. Railroads will also have failed, as their bridges will have been destroyed, and parts of the lines will also suffer sinking as they are next to the Columbia, Willamette, and other rivers. So, evacuating millions of people will not be possible, via North/South routes.. What about East (West will also be impossible as that is closer to the fault and will totally have been wiped out.). Well, guess what, there is no viable route East. How about long term? PGE Engineers said that power would take about 3 years to bring back. So, even if water and sewer lines had not been broken (which of course they will have been totaled) no pumping could take place. People will be stuck, no way to get in to deliver aid, no way for them to leave. Remember that 3 day emergency supply you are supposed to have?? Won't do you any good.

That moment you realize the 2012 Mayan calendar probably meant 2021.

I live in thousand oaks CA. Last summer we had a large earthquake and it literally felt like my upstairs apartment was swaying up and down like i was on a boat. I yelled out to God and i begged him for mercy. It is a very helpless feeling when you are in your bed and then yhe house is shaking and i live alone, so im scared because honestly i think a big one is coming soon.

I was hoping for more GRAPHICS in this Geographic episode.

In Portland, we say "if the ground shakes, look to the mountain." Not only is Cascadia due, but so is Mount Hood erupting. So either quake or volcano eruption, your pick.

1:45 - Chapter 1 - The orphan wave 4:35 - Chapter 2 - Shadow of the thunderbird 8:15 - Chapter 3 - The beast below 12:40 - Mid roll ads 13:50 - Chapter 4 - Finding the fault 17:10 - Chapter 5 - Disaster 20:00 - Chapter 6 - Drowning man

Dear Simon! How are you? My name is Orestis Dionyssios Vonk. I am half Dutch half Greek. Mother is Greek and my father is Dutch. I live in the Greek island of Zakynthos (very famous by a lot of your drunk fellow countrymen 😜) this island wat hit by a huge earthquake in August 1953 . Also the neighbouring islands of Kefalonia and Itaka (island of Odyssey) tens of thousands of people lost there homes. Honderds died and thousand left for other countries for a beter life! 90% of the infrastructure of these islands was destroyed. The British navy was the first one to help people (thank you for that!) like my grandfather and mother (my mother was born one year after that). It’s a very unknown story in Europe and the world. Yet it was a huge disaster for people who had just suffer: A Nazi Germany and Italian occupation and a Greek civil war! I always watch your videos. I have learnt so much from you (thank you for that too :) I really hope that you want to look in to this subject!

Thank you for this important information

"Mostly quiet, but occasionally apocolyptic" - Simon 2020

Although the events were terrible, it is awesome how these mythologies from the people in the Pacific Northwest helped scientists to track down an earthquake from over 300 years ago.

Wondering how many ppl will be here watching after Turkey and Syria today 2/6/23

this is great information!!!!

It's really nice to hear the oral histories treated as useful records of past events. Growing up in the PNW, it sometimes feels like local history begins in the 1800s and everything before that just gets relegated to a very impersonal archaeology.

Well, we can cross that general area off of my "possible places to retire" list.

Very interesting and inforative. Thank you.

Growing up in LA and now in Seattle, I do wonder how the years that have gone by affect the probabilities of this happening. I remember the 1994 Northridge (a 6.7), and living only a couple of miles from DTLA, it felt like a rocking on a pendulum, that started out of nowhere. Visited family in Northridge and in the same block one house was ok, the next one completely destroyed. That one helped that it happened at 4:30am, and the destruction on the freeways was minimal. I think only one guy on a motorcycle was injured as he was on the 110. Now, to think of this one....there are no words. With the ground moving so much, and so many hills with giant rocks embedded into the soil itself... I am a couple of hills and and about a mile East of the 5 currently, in a building that finished construction last year. Wont be in the clear, but I do hope that I would somehow survive...

You didn't mention that along this earthquakes zone from California to Canada, there are seven active volcanos. Some of them will erupt.

Future Humans: We stopped global warming! Earth: Great! Here's a mega quake for you guys to play with

I leave near Seattle, and I remember the 2001 Nisqually quake, an intraslab earthquake had a moment magnitude of 6.8. It was interesting, but not terribly destructive - thankfully - due to it being that type of quake. However, seeing waves going down the freeway from my office building was wild. Unfortunately, my house was built before that 1994 increase of building standards. At least my house is 600 feet over sea level, so flooding shouldn't be a problem at my place!

very enjoyable program and programs, as I listen to your episodes often and always enjoy them, good science and info. as well as human stories and humor

Me: I'm shook Simon: Not yet you aren't

"Other than that, Mrs. Lincoln, how was the play?"

“There are multiple ways for Cascadia to rupture; from ahhhh to EUGHGHHH” 😂😂😂😂 Oh Simon, you crack me up x

I live 2 blocks east of I-5 in Seattle. Thoughts of this event literally keep me up nights.

"If you live in the PNW you've probably never experienced a 4.0 quake". Me distinctly remembering my house violently shaking a few months ago from a 6.5 magnitude quake...And there's been two 4.0 quakes in the last 3 days.

Remember when we welcomed in 2020 with hopes it would be better than 2019?

I know this is an old video but the part where Simon says the average person in the northwest has never felt a quake over 4.0 is nuts. I think just about everyone in Oregon and Washington felt the Nisqually Quake of 2001 which was under a 7.0 but was widely felt and occurred for more than a solid minute

I live in Western WA. Grew up just west of Olympia. The Nisqually quake might not be the biggest thing out there, but at 11 years old, it was a huge deal, and my only first hand experience. We were in school that day. There were two emergency drills that day; one was a lock down, other was fire. Coming in from the fire drill I remember saying something like "what's next, an earthquake drill". Seemed like 5 minutes later, but the earthquake was no drill. Mostly brick school took a fair bit of damage but nothing fell. Mom worked at the school, so me and my sister were home pretty quickly. House was fine other than the 500 gallon propane tank on its side. There were a couple aftershocks, the biggest of which I slept through. Woke up with my bookcase on the bed lol. I think that event as a whole sparked something in me, because to this day I love natural disasters. Not the deaths... that would be horrible. But the intense and raw nature is a big rush for me. Been through a tornados in the midwest (minor but it came right through the back yard) and even though I was old enough to know better, I would have been out playing in it if my mom didn't have a hold on me like Thanos holding his gauntlet. Floods, windstorms, ice storm...especially when power is out for weeks, I love it.

I am a land surveyor and civil engineer in Western Oregon near Salem. I have discussed 'the big one' with many people, and I am constantly astounded at how little people know about it. Most of the people have never even heard of it, and if you discuss it, most think that you are a crazy conspiracy theorist. That's because 'the big one' is almost never in the news.

Living in Oregon all my life, there's this funny comfort and discomfort people have. East coast, you get hurricanes and giant snowstorms, further west you get tornadoes and more snowstorms, down in Cali it's earthquakes and fires all the time, but here in the PNW it's always quiet. It just rains a lot. But there's that looming idea that one of these days, one of those volcanoes are gonna go off again or that that big earthquake is gonna hit and everything is gonna go tits up immediately. I'd rather take this than dealing with a new hurricane ever year honestly.

According to 2 Japanese earthquake preparation specialists I worked with for a few months, we have been lied to. They said we should be expecting a strength of 11 to 11.5 when the "big one" actually happens. The question for British Columbia will be which areas will be hit by the failing dams in the province. BC Hydro doesn't believe the older major dams in BC would survive a catastrophic earthquake...so that means Bennett Dam, Mica Dam and Revelstoke Dam may all fail. I'm not sure which is the more frightening scenario!

Biggest I've lived through on the North Coast of California was in 1992 at 7.2 on the Richter scale. Pretty significant and we've had quite a few more that almost matched that since then.

I'd imagine that the longer Cascadia goes without slipping, the more energy is stored up, and that "overdue-ness" becomes a death-o-meter.

From "auhhh" to "AaAAAHHHH!" This needs to become an official system of measurement - level x Simon "AH" 🤣🤣🤣

Coeur years ago we moved from Richmond BC, elevation 0 meters to North Aldergrove, elevation 95 meters or 311 feet. 30 kilometers or 20 miles inland. 🇨🇦

I watched this video in its entirety as I sit atop Snoqualmie Pass in Washington state. I will spend the majority of the following day running along the coastline of the Pacific Northwest, with a renewed sense of care, wonder and thrilling attentiveness.

As a Californian that lives between the San Andreas and Hayward Faults, I keep my dishes in the lower kitchen cabinets and the Tupperware up above. Oh, and a helmet and swim fins close at hand.

I was taking a Physical Geology class during the Diablo Canyon demonstrations. I remember the professor saying that he wasn't a political animal, but the idea of building nuclear reactors in that area was insane. He also liked showing slides of houses perched on cliffs in California and estimating how long it would be before the occupants woke up in the ocean.

Would have been interesting to see a prediction of what the western coastline would look like afterwards. Also, I wonder if the tsunami would travel as far as Australia where I live.

Once upon a time on Vancouver Island I went to see the first Disney starwars film with my mom. 1/3 into the movie there was an earthquake, probably a 3-4 on the scale. Everyone started standing up, putting their snacks down and kind of just waiting to see if there was more to come. My mother - Bless her heart - thought it was some kind of movie effect and didn't notice everyone standing because she was so engrossed in the movie. She looked up at me and just whispered 'that was so cool! How did they do that?!'. She was stunned when I told her it was an earthquake. So funny looking back.

Just retired Navy, living in Bremerton wa. I’m just gonna go ahead and sell my house🏆

My mom was in Alaska during the 64’ quake, she was 11 years old living in anchorage. She said it seemed to thrash her around for what felt like forever even tho it only lasted 5 minutes. Lol “only” that’s a long time for a earthquake.

I was in the eastern Coast Range foothills W of Salem OR for the 1999 Nisqually quake, on the phone with someone 20 miles from it in Washington when the quake started. My friend could see that it was moving South, and how fast, as it reached puddles. He'd thought it was the train at first. We stayed on the phone until the first vibration got to my place along with the noise you don't exactly 'hear', then ran for outdoors. Out in the country there are trees. Poles with powerlines. Streams and ponds held in place by unreinforced berms. Running away from an earthquake sends you out of your building to where there's all that stuff waiting to fall on you, and you run back to the strongest doorway and see small gaps overhead and things that should be structurally squared, but aren't. You end up in the middle of a road on any sort of flat land where there aren't any overhead wires or places the road could collapse into, or out in a pasture that you hope isn't supported by many many feet of wet sand and mud that is being vibrated into bottomless slop. Then you wait, until it seems to have finished, thinking about how there is *no place to go*. Nisqually wasn't even a BIG quake.