Newport, Oregon Coast, Tsunami (Portland: tornado, earthquake, living)

[Lugnuts]

Not sure if this has been posted before but here's a link to an interactive map of tsunami hazard zones:

NANOOS - NVS

Looks like most of Newport is spared but South Beach gets swamped.

[Random_Walk]

Mind you, they're updating a lot of those maps over the next couple of years.

In my neck of the woods, the tsunami evac map has me walking 1/4 mile uphill, and to an assembly area.

In a lot of areas, even at a local level, you'd be amazed at how quickly you can be 50-100' above sea level... where tsunamis would have to be positively frickin' huge to be a threat.

[Steve Pickering]

It is a sure think it will happen. That area is sinking.

[tablemtn]

The closest model we have for likely tsunami height is from the 2004 Indian Ocean quake, and the waves which hit northwestern Sumatra afterwards. That was a 9.1 megathrust event on a faultline near the coast (similar to what would happen to Oregon), and the tsunami waves reached a height of 80 feet, with some gaining another 20 feet after being shoved up by landforms or hills.

So, if you are 100 or more feet above sea level, even a very powerful quake probably won't generate waves high enough to reach you. In fact, the median wave height is quite a bit lower - 40 to 60 feet in most places - going higher in spots where the seafloor has certain characteristics which channel water upward.

[Random_Walk]

Originally Posted by Steve Pickering

It is a sure think it will happen. That area is sinking.

When the water finally laps at my driveway (in about ten thousand years, depending on geology) I'll be sure to revise my living arrangements.

[Random_Walk]

Originally Posted by tablemtn

The closest model we have for likely tsunami height is from the 2004 Indian Ocean quake, and the waves which hit northwestern Sumatra afterwards. That was a 9.1 megathrust event on a faultline near the coast (similar to what would happen to Oregon), and the tsunami waves reached a height of 80 feet, with some gaining another 20 feet after being shoved up by landforms or hills.

True indeed. Most evac areas sit at 50-60' ASL to account for median wave height, but getting 100' up or more would only take an additional 10-20 minutes' walking up a trail in most cases. You can get to 200' in pretty short order if you're young and healthy.

Out in my spot, it's fairly vanilla, terrain-wise. We face the ocean in one long, nearly-straight line. Aside from two large lakes, a wetland linking them, and numerous smaller lakes, there's no real out of the ordinary terrain features.

[SETabor]

Faster than the sinking is wave and wind erosion. Bluffs above the ocean look great and have awesome views but tend to lose feet fairly quickly.

[Lugnuts]

Originally Posted by Random_Walk

Mind you, they're updating a lot of those maps over the next couple of years.

In my neck of the woods, the tsunami evac map has me walking 1/4 mile uphill, and to an assembly area.

In a lot of areas, even at a local level, you'd be amazed at how quickly you can be 50-100' above sea level... where tsunamis would have to be positively frickin' huge to be a threat.

Unless it strikes at 3 in the morning and you're a heavy sleeper. Fifteen minutes isn't much time:

Video: Risky Business in the Northwest | Watch PBS NewsHour Online | PBS Video

[Lugnuts]

Another interesting segment about liquefaction:

Video: Would a Major Earthquake Sink Portland in Liquefied Soil? | Watch PBS NewsHour Online | PBS Video

[Random_Walk]

Originally Posted by Lugnuts

Unless it strikes at 3 in the morning and you're a heavy sleeper. Fifteen minutes isn't much time:

Video: Risky Business in the Northwest | Watch PBS NewsHour Online | PBS Video

You'd have to sleep awful damned heavy to snooze through a 6.0+ Earthquake.

I get what you mean, though. But all that said, hell, most places on Earth are death traps (example? Growing up in NW Arkansas meant tornadoes, and they do have a habit of sneaking up on you at 3am: Fort Smith Tornado 1996 | Tornado Kills 4, Injures 50 in Arkansas - Los Angeles Times )