Questions about the coming earthquake (Seattle, Bellingham: 2015, apartment, how much)

[KonaldDuth]

I've heard some scary predictions that the state government has put out recently, like that 45% of our state's hospitals will collapse (physically) and damages will be $200 billion. But I'm still having trouble understand the bigger picture about how I should plan my life considering that I plan on living here for at least another decade.

(1) To what extent will the local businesses be affected? For example, will Amazon move to another city?
(2) Will new apartment buildings (built in past few years) be able to withstand the quake?
(3) What exact neighborhoods will be engulfed by the tsunami?
(4) How fast would the economy be able to rebuild itself? A matter of a couple years or a matter of a couple decades?

[dozerbear]

Originally Posted by KonaldDuth

I've heard some scary predictions that the state government has put out recently, like that 45% of our state's hospitals will collapse (physically) and damages will be $200 billion. But I'm still having trouble understand the bigger picture about how I should plan my life considering that I plan on living here for at least another decade.

(1) To what extent will the local businesses be affected? For example, will Amazon move to another city?
(2) Will new apartment buildings (built in past few years) be able to withstand the quake?
(3) What exact neighborhoods will be engulfed by the tsunami?
(4) How fast would the economy be able to rebuild itself? A matter of a couple years or a matter of a couple decades?

These questions are all but impossible to answer accurately, as there are a huge number of variables but I'll take a stab at it anyway.


There are dozens of earthquake faults in Washington, but two potentially the most dangerous. One is the Cascadia subduction zone, that runs 800 miles from northern California up to British Columbia. This fault can produce quakes of 9.0 or better about every 300 years, the last one January 26 1700.

The other is the Seattle fault, that runs from Puget Sound under downtown Seattle, east to beyond Issaquah. This can produce quakes up to 7.3, the last one happened between 900 and 950AD. In that quake some areas sank into Puget Sound while others rose; parts of Bainbridge Island were thrust up over 30 feet, and there was a huge landslide from Mercer Island into Lake Washington.

(1)Not a clue. I doubt the businesses do either, they would have to make that call after the quake when they know how much damage occurred, how long it will take to get up and running again, ect.

(2)New buildings *should* hold up better, but nothing is earthquake proof. Too many variables to say for sure. Also, buildings that survive the quake could be destroyed by fire from broken gas mains, as there may be no water for fire sprinklers, hydrants, ect.

(3)I attached a map that shows estimated water depths up to 16 feet, in a magnitude 7.3 quake.

(4)Impossible to know, would depend on how severe the damage is.

[Hemlock140]

No one, including the state can predict when or how severe the "big one" will be, but there have been many scientific studies with computer modelling. Apparently a tsunami would bring a wall of water into Elliot Bay, which would inundate Harbor Island, then wash back to the northern end, then continue back and forth until it settled down. In that scenario all of the waterfront would be affected, but the worst would be Harbor Island to Alki, and Smith Cove/Magnolia as in your map. I work on Elliot Bay, and this threat has not affected my enjoyment of working on the waterfront. With the current earthquake standards most newer building should survive, but there are still many old, brick buildings that suffered from the minor deep 6.7 Nisqually earthquake of 2001, that couldn't take anything much stronger. Having been through the 1989 Loma Prieta in California, and seeing the devastation there first hand, I still don't worry about it much, because there isn't anything that can be done about it. It may happen today, or it may not happen until we are long gone.

[KonaldDuth]

Ok, what I'm hearing is "we have no idea", so my best guess is that there's a 50/50 chance my apartment collapses into rubble on top of me.

[NWarty]

I'm not going to sugar coat it. A magnitude 9.0+ earthquake, shaking for five minutes, will level the Puget Sound region and basically thrust us back into the dark ages for a year.

The Earthquake That Will Devastate the Pacific Northwest

Read this article, then read the follow up article.

I worked the CSZ exercises this past summer. Yes, if the big one hits, with the predicted strength, it'll be ugly.

[AADAD]

We saw some of this effect in the Loma Prieta Quake. The problem there was homes built near the Marina. Many collapsed (and caught on fire). Large buildings which shook were relatively unscathed. The order of magnitude of a 9.0 will be two keypoints. Depth is the 2nd. Distance is the first.

Within 200 miles of the coast of Washington a 9.0 will devastate much of the infrastructure in the immediate Seattle area and depending upon the length of time in the latter waves will increase destructive force. Not many older buildings will be left standing. Larger skyscrapers built after 1980 should fare ok but plan on falling glass.

The tsunami will devastate Bellingham and the West Coast of Whidbey Island. The safest place to be will be in a home built on rock or substrata above 200 feet.

Survival in any urban area will depend on your preparation and planning. Count on walking or running. If youre at ground level on't attempt to retrieve your car. Know how you will move to higher ground. You should carry 24 hours rations and ways for others to locate you. A small backpack under your desk or in your car really is not that heavy.

Most people die from the water in a tsunami not from the shaking. Don't go below ground to get your car. In a building if the shaking does not damage it stay there and move to upper floors. The tsunami is coming. Don't leave, don't go to the street and if youre able make contact with loved ones. Frequently local towers won't work but long distance signals may get through.

Have a plan.

[misscross]

it is good to have a plan and be prepared for an emergency.

search DNR WA geologic hazard maps there are maps about earthquake zones, fault lines, tsunami effects here.

Most of the Eastside will be a whole lot less affected than Seattle proper generally speaking, if you look over a number of these maps you'll see why. A 9.0 earthquake is nothing to sneeze at and we will all be affected, but I'm happy to be living away from Elliot Bay.

[Hemlock140]

Originally Posted by misscross

it is good to have a plan and be prepared for an emergency.

search DNR WA geologic hazard maps there are maps about earthquake zones, fault lines, tsunami effects here.

Most of the Eastside will be a whole lot less affected than Seattle proper generally speaking, if you look over a number of these maps you'll see why. A 9.0 earthquake is nothing to sneeze at and we will all be affected, but I'm happy to be living away from Elliot Bay.

We are at 600' elevation on solid bedrock, and bought where we did with earthquakes in mind. I just have to hope it happens when I'm not at work, or after I retire in 3-4 years. I actually thought about tsunamis when my waterfront office moved from the 3rd floor to the second. The altimeter shows me at 17 feet in my office.

[OneTimeSEALover]

They say this stuff about California. But look at what HAS happened. Sure Northridge was gnarly with the collapse of a two layer bridge. 1906 was a disaster due to fire. And the one that hit in the World Series was nothing to sniff at. BUT. Look at LA and San Francisco today. And look at Alaska that got one of the biggest ever. Civilization picks up and goes on. Ironic thing is that the homeless in their tents might be safer than the millionaires in their penthouses.

[pnwguy2]

Originally Posted by NWarty

I'm not going to sugar coat it. A magnitude 9.0+ earthquake, shaking for five minutes, will level the Puget Sound region and basically thrust us back into the dark ages for a year.

The Earthquake That Will Devastate the Pacific Northwest

Read this article, then read the follow up article.

I worked the CSZ exercises this past summer. Yes, if the big one hits, with the predicted strength, it'll be ugly.

You have been misinformed. A 9.0 subduction quake would be at that strength on the Washington coast. Fortunately, the coast does not have a large population. (Oregon is much more at risk on the coast with greater population there). The Puget Sound region, where Seattle is located, is not the coast. While there will be damage, "level the Puget Sound region and thrust us back into the dark ages" is inaccurate. The tsunami waves even with a 9.0 quake would be greatly reduced by the time they reach Seattle. I am not trying to minimize damage in the Seattle area, but the overly dramatic reports have been denounced by most scientists. The New Yorker article you linked to has been generally debunked, and the follow-up somewhat explains this.

Further this quake may or may not happen in our lifetimes. The general timeline is 300-500 years, but I have heard other predictions of 300-700 years. The last great one was 1700. Do the math and you will see it could happen tomorrow, but could happen a couple hundred years or more from now.