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Comment by edgyswingset | Hacker News Reader

I don't think a tsunami is going to flatten the city. A wave has a lot to go through (peninsulas, narrow straights, etc) before it could reach the city, all of which would likely lessen its impact significantly. Where the area will get hit hard, though, is liquifaction and landslides.

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There will be significant damage from water all around inland Puget Sound, though I agree not on the scale of the full-blown tsunami on the coast. Everything is going to shift 30 to 100 feet west over the course of a couple minutes - the water in Puget Sound is going to slosh around like crazy.

Tsunami inundation maps: http://wa-dnr.s3.amazonaws.com/Publications/ger_tsunami_inun...

For Seattle, it's south of Downtown, Pioneer Square, the Duwamish industrial areas, and Interbay.

But the density of (destroyed) infrastructure and loss of power/water/sewer would be a much bigger problem citywide.

Narrow straights would actually increase the damage, as was the case in the '64 Port Alberni(vancouver island) tsunami.

Yeah, and the Elliot Bay tsunami hazard map[1] is a nice reminder that most of Seattle is up some steep hills (including flat areas like SLU). The hazard map models a 7.3 earthquake on the Seattle fault, which is tiny compared to a 9.0 in the subduction zone, but also doesn't have to travel through all those narrows straits and turns.

[1] http://www.pmel.noaa.gov/pubs/PDF/wals2794/wals2794.pdf

Tsunamis are not like normal waves. I think they might be more like a really big rise of the tides.

Tsunamis are in fact a lot like waves, just real big ones. Tsunamis move quickly, a tide does not.

I meant in the amount of water shifted - so you don't simply break a Tsunami like a wave, the water just keepscoming.

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