Seattle On Shaky Ground


A reader writes:

Another headline you won't see: "Millions saved in Seattle by good engineering and government building codes". California is thought to be safe from >8.0 earthquakes (but even 6.x quakes do quite a bit of damage). The Pacific Northwest, on the other hand:

A magnitude 9.0 or above quake in the Pacific Northwest is expected. Those quakes, which are the product of vast and deep faults, are characterized by their severity and the duration of shaking when they strike. ... A quake in the 9.0 range occurs in the Pacific Northwest region every 300 - 500 years. The last one was in 1700, which scientists know because of a tsunami that was recorded in Japan at the time.

Current Seattle building codes are probably pretty good, but older buildings - and there are more than in Japan because the city hasn't ever been hit by a devastating quake or war - are at heavy risk.

The estimated damage:

A study from 2008 indicates that as many as 1,000 buildings in Seattle could fall down in a strong earthquake. In that study engineers looked at 575 buildings from the outside and further that estimated 850 to 1,000 old brick buildings that date back to the 1930s would be at risk if a 6.7-magnitude earthquake occurred on the Seattle fault, which runs through the center of Seattle and Bellevue.

The Seattle fault is widely considered the most dangerous quake threat to Seattle. Scientists have predicted that a significant earthquake on this fault could cause widespread devastation and at least 1,000 deaths in the city because of collapsed buildings, fires and other infrastructure failures. ... In October the Washington State Department of Transportation released an animated video showing what could happen to the Alaskan Way Viaduct during an earthquake.

Photo by Flickr user Jeff Greene, who captions:

This is an impression from my window at the Seattle Sheraton, where the Marketing Association of Credit Unions was holding its spring 2007 conference. A button in each elevator at the Sheraton says "push in case of earthquake," which scared us East Coasters to no end.

One of those buttons here.