6 ms·

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

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.

saintgimp 11y ago
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.
- deleted 11y ago
  [deleted]
  - olefoo 11y ago
    Large parts of downtown and the area between Queen Anne and Capitol Hill ( where the Amazon campus is ) are built on fill, and are likely to be subjected to liquefaction in a major seismic event. It's entirely possible that whole sections of Capitol Hill could slide into downtown too. The hills shake and the mountains dance, and then comes the tsunami; this sounds much more exciting to read about than live through.
    - nkrumm 11y ago
      Here's a map of liquefaction risk in King county: http://your.kingcounty.gov/dnrp/library/water-and-land/flooding/local-hazard-mitigation-plan-update/liquefaction-hazard-map.pdf http://your.kingcounty.gov/dnrp/library/water-and-land/flood...
      - pnathan 11y ago
        Thanks! I was going to be googling for that shortly. :-)
facepalm 11y ago
Tsunamis are not like normal waves. I think they might be more like a really big rise of the tides.
- chrismcb 11y ago
  Tsunamis are in fact a lot like waves, just real big ones. Tsunamis move quickly, a tide does not.
  - facepalm 11y ago
    I meant in the amount of water shifted - so you don't simply break a Tsunami like a wave, the water just keepscoming.
dgraunke 11y ago
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 http://www.pmel.noaa.gov/pubs/PDF/wals2794/wals2794.pdf
soperj 11y ago
Narrow straights would actually increase the damage, as was the case in the '64 Port Alberni(vancouver island) tsunami.
pchristensen 11y ago
Tsunami inundation maps: http://wa-dnr.s3.amazonaws.com/Publications/ger_tsunami_inundation_maps.pdf 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.

saintgimp 11y ago

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.

deleted 11y ago
[deleted]
- olefoo 11y ago
  Large parts of downtown and the area between Queen Anne and Capitol Hill ( where the Amazon campus is ) are built on fill, and are likely to be subjected to liquefaction in a major seismic event. It's entirely possible that whole sections of Capitol Hill could slide into downtown too. The hills shake and the mountains dance, and then comes the tsunami; this sounds much more exciting to read about than live through.
  - nkrumm 11y ago
    Here's a map of liquefaction risk in King county: http://your.kingcounty.gov/dnrp/library/water-and-land/flooding/local-hazard-mitigation-plan-update/liquefaction-hazard-map.pdf http://your.kingcounty.gov/dnrp/library/water-and-land/flood...
    - pnathan 11y ago
      Thanks! I was going to be googling for that shortly. :-)

facepalm 11y ago

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

chrismcb 11y ago
Tsunamis are in fact a lot like waves, just real big ones. Tsunamis move quickly, a tide does not.
- facepalm 11y ago
  I meant in the amount of water shifted - so you don't simply break a Tsunami like a wave, the water just keepscoming.

dgraunke 11y ago

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

soperj 11y ago

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

pchristensen 11y ago

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