Seismic fault beneath US is ‘fully loaded’ after 311 years

“It’s been 300 years,” Bill Steele said Tuesday. “We have a fully loaded subduction zone.”

Actually, it’s been 311 years since the Great Cascadia Earthquake of 1700.

Steele, a University of Washington seismologist and spokesman for the Pacific Northwest Seismic Network, said scientists have determined the monster quake occurred Jan. 26, 1700 — 311 years ago tonight.

It happened off the Northwest coast, and created huge tsunamis that devastated shorelines here and in Japan.

heraldnet.com...

Check. It's easy as the days go by to forget what a risk there is of living in this area.

Steele said it takes hundreds of years to build up the strain that causes a subduction zone earthquake. “The toe of North America, the edge, is being shoved downward. It’s like bending a ruler back,” he said, adding that the 1700 quake was the last one known to have occurred on the Cascadia subduction zone.

Remember — it’s “fully loaded.”

“It could produce another one tomorrow, or maybe a century or more away,” Steele said. “Certainly geologically, in the not too distant future we’re going to have another one.”

Steele is all for being prepared — whether it’s keeping supplies on hand at home, making sure homes and public buildings are up to withstanding big quakes, or assuring that people who live on the coast have evacuation routes.

It takes money, and recognizing the risks.

“Our purpose here is not to scare people,” Steele said.

The recent quakes in Vancouver could be real bad signs of things to come, as it lies on an extension of the Cascadia fault. The fault could produce an enormous quake, and clearly, it is ripe and ready. With every day that passes, we are one day closer to the energy release. And it could be worse than anyone thought.

Currently, the largest quake ever recorded was a 9.5 in Chile back in 1960. This zone has the potential to equal or exceed that, based on the length of the fault alone. But to make matters even worse, the recent 9.1 in Japan was unprecedented. It surprised even the most skeptical scientists, because no one believed a quake that big could happen on that length of a fault. But it did.

And because of Japan, scientists are being forced to re-evaluate faults lengths and potential quake magnitude relationships. They don't know it all, and the study of quakes is extremely limited in a historical sense.

What if on the next round, the intial quake is so damn big it triggers a tearing of the entire fault? In which case, goodbye Chile 1960 as the biggest quake ever.

reply to post by TrueAmerican


Human 0815 wrote as follows:

Chance for big tsunami in eastern Japan within 30 yrs revised up to 30%


TOKYO (Kyodo) -- The probability of a major earthquake occurring and triggering a massive tsunami in the Pacific Ocean off eastern and northeastern Japan within the next 30 years has been revised up to 30 percent from 20 percent, a government panel said Friday.

The Earthquake Research Committee has reexamined its long-term estimate of killer temblors after the March 11 quake and tsunami and found that a quake that triggers a tsunami as powerful as the one caused by the 1896 Meiji-Sanriku Earthquake, which killed more than 20,000 people, is more likely to happen in the sea zone stretching 800 kilometers north-south.

mdn.mainichi.jp...

They try to build big Shelters now, massive Structures who can stand this huge kinetic Energy
from the Tsunami Wave!

At 03/11 a few Tsunami-Shelters got washed away, incl. this poor People inside,
mostly old People and very young Students
I do not know so well

Followed by this:

They do not speaking about a huge EQ.
they predicting a "Huge Tsunami"
which will be really catastrophic, much more than 03/11.

I hope that they renew the Protection in time!

Is Japan beginning preparations for this Huge quake to come?

And one more thing: I don't mind being called a fear monger much over this subject, so if you must, go ahead, accuse me. I am guilty out of choice on this topic. I want to be. I want to strike fear in the minds and hearts of every single person living in that area at this time, because the time is near. They know this fault well, have studied it profusely, and historically it goes about every 300 years. It's been 311.

Ignore the warnings at your own peril. But fearmonger TA tried. I did.

And lastly, one more time I will rest my case, with Find A Place.

!!!

yep it's true, i'm ready for the "big one".

last earthquake that we felt was February 28 2001,

en.wikipedia.org...

I'm in metro vancouver, I was sitting in a grade 5 science fair when it started to happen at 10:54 A.M during a presentation for Earthquakes. it's BS cause they won
my desk started to wobble, then shake, then the lights began to sway.
I was the first under my desk, I knew right away.

But the big one will be nothing like that. that earthquake last like 30 seconds-1 minute.
the big one will last 5 minutes at a magnitude 8.0+

Yup. I've been trying to get as much info out there as possible the past couple of years. ATS is one way, word of mouth, facebook and other on-line media (local papers) are others. Having lived in Washington State for most of my nearly 40 yr life and in the NW corner for over twenty-five now, I think I have a good handle on the local take on all of this:

TOTAL AND COMPLETEL IGNORANCE

Seriously. I would guess over 75% of the populace is completely unaware of the real risk, and most likely over 80% are not at ALL prepared for this type of natural disaster. I am being conservative in my numbers. The reality is probably even worse.

With the recent quakes in Vancouver you mentioned, I upped my mantra to friends and family about what may be coming any day now. As the article states; it could happen tomorrow, or 100 yrs from now, but history shows it will most likely be sooner than later. After the last 6.4 in Vancouver, I started a thread regarding the possibility it could be symptom of a MUCH bigger problem:

Is the 6.4 Vancouver quake a sign of things to come?

Ofcourse, there is also LOTS of thoughts and theories in my Washington thread, found in my signature.

Thank you for the reminder....and no, I do not think you a fearmonger, rather a reality check. This is not a matter of IF, but WHEN. It simply amazes me how people living right on TOP of this monster or so oblivious to what will happen.

reply to post by westcoast


Imo, the USGS should be issuing regular warnings to people over this. How regular, I don't know, but at least once a year. At the very least. And the media needs to reinforce this.

I know it is very bad for business, but more people need to get a clue. You figure the Tsunami Evacuation Route signs would get the people's attention to study more. Who knows, maybe the ancestors had "tsunami stones" on the hills like in Japan. And maybe those are at the bottom of the sea now.

TA - I hope you ignore the people who just want to call you a fearmonger while adding nothing to the conversation. I have followed both you and Westcoast on these PNW quake warnings as well as other sources. I have instructed my wife and children on what to do in case we get hit - whether it's the "big one" or just a decent quake, and I am usually stocked with enough to feed us all (family of 5 plus daughter's boyfriends) for at least 2 months. If nothing happens, then I have some extra food on hand anyway.

I think these warning threads are a good time to also post some basic survival ideas too in case of a big quake. Aside from storing the food, my family knows that once the shaking stops and the house is still in good shape it is a good idea to stop up all the sinks and bathtubs and fill them before doing anything else. That way you have a good amount of clean water on hand in case the water gets interrupted or shut off in addition to whatever stored/bottled water you have on hand. Just one of many emergency plans we have for whatever emergency may hit.

Maybe a good "what to have on hand in case of emergency" thread might be helpful too where everyone can add their own ideas/preparations.

Thank you for pointing this out. I too live in the PNW, Seattle, and living in a college dorm doesn't lend itself to EQ preparedness... In my experience, people know that earthquakes are dangerous in this area, but they have a "never gonna happen" attitude that causes them not to prepare. Also, people inside the Puget Sound don't even realize tsunamis are possible here (when my dad told me that when I was younger I thought it was a joke.) The Olympic Peninsula is much more susceptible to dangerous tsunamis but the Puget Sound has water too, so though the tsunami danger is much lower and likely the tsunami would not be as big in Seattle, it could still happen, especially with a big enough EQ, and places like Pike Place Market would be gone!

In response to the last couple of posts, and thanks for your comments:

The more you study subduction zones and understand where and how these megathrust quakes occur, the scarier the situation in Cascadia becomes.

1) First, there is the stress buildup. Of that there is no question. 311 years is a pretty good while for no real big quake on that boundary.

2) But a crucial number two is understanding that the epicenter of this quake may even be directly under land. That would be one worst case scenario. But if you look at where the epicenters of massive quakes on subduction zones have historically occurred, they usually occur many miles towards shore from the actual subduction zone line at sea.

This is because the stress builds up under the lip of the subducting plate, as the subducted plate keeps pushing more and more underneath it. The rocks finally just can't handle it and it goes in a megathrust. In Cascadia, that region of overlap puts a likely epicenter either in pretty shallow water, or directly under land itself. And both cases are bad. It means that the quake is likely going to have near maximum effect and wreak untold devastation- and a likely tsunami will ensue, even if under land. If in shallow water, and a 9+ hit, the tsunami could dwarf what Japan or Indonesia witnessed. I am talking 100 ft or more.

It really depends on the exact hypocenter location and depth, but either way, it is a very dangerous situation. I guess the silver lining is if you survive it, then you'll have put up with massive aftershocks for a year or two- but after that you'll probably have another 300 to 600 years without much incident.

Oh. Also, in regards to Tacoma area and sea inlets:

Very, very bad to be anywhere near inlets, coves, harbors, bays, and anything of the sort. These types of geologic features will concentrate the waves, making them even bigger. Cause the water has no place to go but up. We saw several cases of this in Japan. If it was really bad, starting with a 100 ft wave, places like that could see 150 ft or more.

One example of how blind people are:

We DO have evacuation route signs. They are small, white/blue signs (white blackground with a blue wave). They are scattered all over the place. I have pointed these out to a couple of friends and although they have lived here for years, and the signs have been there for several years.....they never noticed them. People are completely blind to what they are or what they are for. Unbelievable.

I used to live in Washington. I would hear about earthquakes that happened there occasionally. When I was 4 or 5, I wanted to experience one. I eventually felt the 5.4 in 1995 when I was 7. Most people are under the impression that earthquakes don't happen in that state. When I moved to Oregon and then to California, not once did I hear about the Cascadia Subduction Zone in school. It's amazing that something so dangerous is completely unknown to most people all along the west coast. When I read that the biggest mega thrust zone currently known was right off the west coast, I thought that they had made a mistake...

reply to post by OneAndCreakily


I remember that one, I think it was the Scottsmills earthquake, woke me up from a nap

I sure hope we have lots of little ones as apposed to something catastrophic (I be in WA atm) preferably a hole bunch around 3 or whatever isn't really noticeable to ease out all the stress.

What would a 9+ earthquake on that fault line feel like in Portland or Seattle? Like a 6.0? Enough to cause massive building damage to those buildings that weren't built for Earthquake resistance.

reply to post by TrueAmerican

and historically it goes about every 300 years. It's been 311.

OOOHHHHH! 311 years...March 11...hmm...what happened to all the numerology people?

Edit: Did I miss something?

Jan. 26, 1700 — 311 years ago tonight.

Is it January? *Facepalm*

Found a shade more info concerning this a few days back. Found by first reading Extinctionprotocol 2012 - read down via Comments and this , was suggested;

www.islandssounder.com...

A while back, I recall people (on ats here) asking about the origin of this then mysterious map of a changed US, due to the major geological movements.

So here is a vid of the interview with the originator of that story. He is Tim Spencer, a US Navy veteran, of the Submarine Corps. Who says that while he was working in New Orleans on duty, he came into this info. It looks like the entire country is ripped nearly in half through the MidWest, and a huge chunk blown out due West. During a classified briefing he heard "Gentleman, this will happen during your lifetime."

Originally posted by TrueAmerican
I don't mind being called a fear monger much over this subject, so if you must, go ahead, accuse me.

In general, in my opinion, you tend towards fear mongering. And on more than one occasion I've posted to that effect.

In this case, however... I've got to agree with you.

Damage that I've incurred due to earthquakes has been down to one thing: complacency. When you don't get a tremor for a couple of months, you start to forget. Things get put back on the top shelf, the computer monitor gets moved, get in a new bookshelf and forget to buy the kit to safety chain it to the wall, leave the gin on top of the fridge... and then you come home from work to find all of it lying on the floor. Including the gin, which makes cleanup that much more heartbreaking.

It happens. And although it's inevitable, it's possible to limit the damage you experience without going all tinfoil hat survivalist. Vancouver WILL have another large quake. That's a certainty. But because it hasn't happened in living memory, people aren't ready.

Here is what I'd suggest:
1) Live somewhere that's up to code. Old buildings are cool and all, but there's a reason you don't see too many houses over 40 years old in Japan: they don't last, plain and simple.
2) Avoid brick. That crap just crumbles. If your house has brick siding, you might want to reconsider where you park your car.
3) Heavy stuff goes on the bottom shelf. Light stuff on the top. Always. Breakables close to the ground.
4) Tall shelves (freestanding) should be anchored to the wall with a strap - think something plastic about 20cm long. Leave a bit of play in it, anchor one end to the shelf and the other to a stud. Easy. It won't support the shelf, but it -will- kill the shelf's momentum. That's enough to keep it upright.
5) Castors. Buy lots. Put them on anything you can think of - TV stands, stereo, computer table, fridge, etc. Don't lock the wheels. When a quake happens, the wheels will just turn, and the movement of the furniture is considerably less. Of course, if you've locked all the wheels, forget it. This works very well, and really is the reason I didn't have to replace my computer in March.
6) Evacuation route. Learn it, maybe walk it once or twice. Know where it is at least.
7) Emergency crap: I keep a case of water jugs on hand, and replace it as I use it. Keep some batteries on hand, and enough food to last a couple of days. Average Canadian winter preparation, at least if you grew up in a rural area.
8) Start today. Make a sweep of the house on the day you change your smoke alarm batteries, and look for things that might come down/fall apart in a quake.


tldr: prepare for the worst, hope for the best.

reply to post by TrueAmerican


What exactly would a tearing of the fault look like/cause?