I would like to clear up some of the misconceptions of the Seattle Ship Canal - near the Fremont bridge its narrow, as little as 30-40 meters, and not terribly deep, but its moderately cold water - swim it, and you need to dry off afterward, a nice trick in October-May in Seattle. FWIW I wouldn't swim it on a dare in August. There is no current, and plenty of pollution - not to mention that after an EQ event, raw sewage is expected to spill into the Canal and Lake Union from ruptured lines in nearby Ballard and Lake Union neighborhoods. But its generally not necessary to swim - the Fremont bridge should still span it, and the Ballard Bridge, and maybe the University Bridge and the Montlake - although the University risks collapse from the I5 Ship Canal bridge collapsing overhead. Of these, the Fremont bridge received the most recent retrofit designed in part to secure the bridge's sideways motion in the event of an EQ, and keep it intact. The Ballard bridge is a double bascule, and the University Bridge hasn't had the retrofits yet (I think), and the Montlake won't be retrofit until later when they finish the Sound Transit rail line across the Montlake Cut. Given their overall distance from the Seattle Fault though, most or all of these spans are expected to survive an M6.5. If we're hit by an enormo subduction zone (e.g. along the Pacific Coast, 200 miles away) EQ, which is probably overdue, all bets are off apparently (no engineering studies conducted for that).

As for boats to carry you across if there is no bridge, maybe - but you have to think like the walking refugee that you are. If you're walking north, so are thousands of others, and the first refugees to spot an opportunistic row boat will have already rowed it to the other side. The best you can hope for is someone who willingly stays in their boat, ferrying passengers across. In Seattle that's the nice thing to do, and increasingly it would be the Seattle thing to charge a ferryman's fee (Nordstroms clothing didn't get their start in the Alaska Gold Rush, they made their early fortune selling grubstakes to miners). It would be an unusual situation for someone to sit on their boat providing that service to strangers.

As for tsumani or seiche risks in the Ship Canal, the data is mixed but tends to minimize possible damge, or loss of life anyway - as you can see on this 2003 Tsunami study of the area, the Ship Canal imposes alot of deflection on incoming waves, so the odds of a tsunami impacting the ship canal doesn't seem high. http://www.pmel.noaa.gov/pubs/PDF/wals2794/wals2794.pdf However, seiche studies (sloshing from distant EQs) record historical impacts on Lake Union and Lake Washington, the bodies of water immediatley inside the Ship Canal, and the record M9.2 Good Friday (Alaska) EQ in 1964 ripped Lake Union houseboats from their moorings, but caused no injuries. http://community.seattletimes.nwsource.com/archive/?date=20021104&slug=quake04m. More recent studies though show that a tsunami originating from the Seattle Fault itself could cause a significant tsunami, wasting for instance the building that Wolfepack works in along Western Avenue, within minutes of the EQ itself. As I said, his work neighborhood will resemble a war zone, and his best bet may be to climb for his life up the hillside, obstacles and landslides permitting. And his climb is complicated depending on how near he is to the Alaskan Way Viaduct, a 1950s era structure that will at best pancake but at worst may fall sideways, toppling and crushing adjacent structures. But you don't need me to fill your head with scary visions of the EQ future for the Viaduct, local politicians have been doing that for years, to the point that Seattle has decided to drill a *tunnel* to replace the viaduct, despite all the soil studies indicating it to be expensive, possibly impossible, and incapable of surviving any sort of EQ. But that's political, and I digress...

This idea of a life line across the Ship Canal is a very real one for emergency planners - the only Level 4 Trauma Center in the PNW, Harborview, is located south of the Canal, whereas a fair number of the injured will be located North of it. So you can bet that it is a priority to secure a crossing point just as soon after an EQ occurs, and survivability has had some priority in SDOT's engineering plan.

Wolfepack mentioned he thinks of the Superdome as a model for future shelters - we don't have a Kingdome (enclosed stadium) in Seattle anymore, and the football and baseball stadia are on some of the most compromised and prone to liquefaction ground in the entire world - worthless as potential shelters. The plan is to employ city parks as temporary shelters, similar to what you see on the TV from Haiti. A certain number of enclosed shelters will also be opened in secure buildings, meant primarily for wounded in Alternate Care Facilities. For the most part, instead of some enormo stadium sheltering folks, they will be directed to neighborhood parks, which will each shelter 200-500 people at most, but there should be alot of them. Again though, alot of the shelter inventory (cots, blankets, supplies) are pre-cached north of the Ship Canal, although I believe they have relocated some of it to south of the Canal since we last looked at their plan. Anyone who actually lives in Seattle knows that sleeping in a park surrounded by 400 neighbors and residents is about as safe as you can get - folks who assume otherwise must not be from around here. But if you don't like the parks, look for a church or business that's intact, and ask politely to be let in, odds are on your side. That's Seattle Nice for ya.