If the Yellowstone Super-Volcano were to erupt Seattle, San Francisco and possibly Los Angeles to the west (depending on prevailing winds), and Chicago, St. Louis, the Twin Cities and Winnepeg to the east might see up to an inch of ash fallout, but that's much less than what we experienced in some places around the state during the 1980 Mount St. Helens eruption. You could pretty much kiss Colorado, Idaho, Montana, and Wyoming goodbye, but who would really miss them?

Seriously though, the more likely impact would be from a potential "nuclear winter" as sulfur aerosols and air-borne particulates block out the sun for several months, and of course these particles will wreak havoc on respiratory systems and mechanical and electronic devices all over North America and presumably beyond. But, Seattle would basically still be standing.

Statistically-speaking you have more to worry about from being struck by a meteor than you do about Yellowstone.

There are more prosaic problems that could cause issues.

The Oso landslide gave us a hint.

Seattle built on seven porous hills (one of which was leveled) is liquification alki.

Pervasive rain from Rainier to Renton brings the whole thing sliding down into the Salish Sea.

what a bunch of pussies.

we have stringent building codes requiring seismic reinforcement. the new buildings might get red-tagged afterwards but they won't fall down during.

Yellowstone is EAST of us. 500 miles EAST. which way does the weather go? EAST.

@2: no. Oso =/= Seattle's hills. our hills had a thick sheet of ice moving over them for millennia. they're kind of PACKED DOWN now. only the steepest slopes (like Oso) are susceptible to slides, not "the whole thing".

ugh.

@2,3 - My understanding is that Capitol Hill is basically granite, which isn't really going to melt, liquifaction stylee, in a quake. OR in rains. Sure, some slopes around Seattle will slide, along with the houses on them, but come torrentials rains or 9.0 quakes, most of the land is mostly ok. I'd be more worried about flooding myself.

More of a problem is the earthquake evidence that the Seattle Fault (under our stadia) could result in a 1-2 meter drop in the land, like it did once before, back in the mists of tiiiiimmme...

That would suck. But hey, ya makes yer choices, ya takes yer chances... Worried about natural disasters? Go live in Idaho or or something.

For what it's worth my newly stressed-out friends, the newer the safer. Tokyo's subway withstood that last 8.9 without severe damage or loss of life. BART was virtually undamaged in the '89 quake as well.

Where you don't want to be is in a old, unretrofitted structure built on landfill—or standing outside of anything brick.

The real threat (other than the Cascadia quake) not mentioned is the Ranier Eruption. The Lahar empties into the sound at the Port of Tacoma and into Lake Washington at Renton through the Kent valley.

In the worst case Ranier Eruption there are something like 130,000 people living in the lahar zones.

i've always been fascinated how the american psyche is obsessed with disaster/armageddon scenarios.

the religious have always preached the original Amageddon (the Rapture, 666, the Beast, horn of babylon etc)

but the educated, the left, and society in general loves to fantasize about any number of mega-disaster, societal collapse scenarios - the Red Scare (commies), nuclear winter, african killer bees, bird flu, ebola, Al Qauadea, bio-terrorism, climate change, aliens, asteroids, GMO food, vaccinations, non-vaccinations.

i've lived in several different /countries and have never seen anything remotely close to the end-of-times memes that we go thru.

Our growing obsession with our doom just might have something to do with the media's growing obsession with the page views derived from overhyping disaster scenarios.

What I am most worried about is a tsunami AFTER a 10.0+ quake... Basically, scientists did some research and found that anything downtown before I-5 is FUCKED...A 10.0+ earthquake would cause a fucking 500+ foot tsunami (picture 1⅓ of the space needle, stacked up on top of itself...basically,a big giant ass wall of water and shit heading towards you) to empty the waterfront area and slam the fucking downtown area and Capitol hill,dumping all that shit into Lake Washington...that is,if the aftershocks don't fuck shit up even more...it can hit anytime, day or night and we are well overdue for it...

@9:

Wrong. They said a tsunami would wreck anything west of I-5 AND south of Olympia. Think about it - we have a entire fucking mountain range between the Seattle Metro area and the Pacific Ocean. No tsunami is coming over the Olympics.

That said, the Sound will certainly swell as water works its through in and anything coastal will get flooded. But there won't be giant walls of water crashing into downtown. Damage from the actual earthquake is the concern for Seattle.

You gotta admit, none of this sounds as scary or as imminent as "President Trump."

@9 "A 10.0+ earthquake would cause a fucking 500+ foot tsunami"

If the Puget Sound Area got a 10.0+ earthquake, the least of its worries is a 500 foot/150 meter tsunami... We would be talking a complete liquefaction of the ground, and huge drops of land. It would be the equivalent of set off a couple thermonuclear device under the Puget Sound Area. The strongest earthquake ever, was a 9.5 in Valdivia, Chile..

Everyone needs to stop taking their paranoia medication, remember the San Juan De Fuca Plate and Cascadia subduction zone is a still off the coast, not in Wedgwood..

#11, the Straight of Juan de Fuca is deep enough and the surrounding land shaped in just such a way that the amount of water entering the Sound during such a tsunami renders the protection from the Olympics moot. In fact it is deep enough that it causes a funnel effect, which is why Olympia and the surrounding area would be so hard hit (being the bottom of the funnel). This is also a large enough volume of water to remove the mitigating effects of the Ballard Locks, causing essentially no reduction in wave size from Seattle to Bellevue.

The volume of water from a Cascadia subduction quake is immense. A movement of 1-2 meters along hundreds of miles of fault line creates a cavitation pocket with more power than a nuclear explosion "inside" of it. Distance is practically irrelevant since we're talking about geographical scale here. Any tsunami originating on this side of the Ring of Fire will hit this coastline with full force, and in roughly 30 minutes.

Wedgewood will be just as hard hit as Ocean Shores. On a global scale, there is simply no effective difference between the two.

@13, well there is the Seattle Fault, much smaller than the big fault off the coast, but with potential to cause major local damage. As far as tsunamis, still more like 2m in Elliott Bay, though.

Nobody is ever "at fault" in Seattle, unless they're hetero crackers.