Yeah then let's try a quake swarm similar to this up and down the New Madrid fault line. It'd be incredibly devastating as well. Last time was December to February of 1811-1812 and was approximately 4 quakes of 7.0-7.5 (estimated) and 7 different 6.0 or greater (estimated) during that 2 month period. Those went from NW Arkansas through Missouri and Tennessee and if you look at the estimated damage maps you'd be talking about severe or extremely heavy damage in Memphis, St. Louis, Indianapolis, Cincinnati, Louisville and maybe Nashville. CSZ, Alaska and New Madrid are the nightmare areas.fasthorse05 said:Not many folks know about the Cascadia subduction zone. When that thing goes, no one in the entire state of Washington or Oregon will be interested in the color or gender of their fellow citizens. The quake would be bad enough, but the tsunami would finish off Seattle for a couple of years.Smeghead4761 said:I think that's the biggest on record in the U.S. That one was actually offshore, IIRC, but the tsunami was brutal.AggiePops said:Alaska, 1964, was a 9.2. I worked with a guy who was a school kid up there during that.Smeghead4761 said:
I grew up in California, and even in a rich, industrialized country where earthquakes are common and planned for, like the U.S. West Coast or Japan, a 7.8 is big. Very big.
The Loma Prieta quake (the 1989 World Series earthquake, for those that remember) was a 6.9. The Northridge quake in 1994 was 6.7.
Since the Richter Scale is logarithmic (each whole number increase on the scale is 10x increase in magnitude), this quake is about 9x as powerful as Loma Prieta.
Even somewhere like California or Japan, with long established and well enforced building codes, the effects would be brutal. In a less wealthy country like Turkey, a big quake like that will be devastating.
Luckily, Alaska wasn't very densely populated. My last tour at Ft Lewis, WA, I participated in a tabletop exercise centered on a major quake (8-9.0) on the Cascadia Subduction Zone, which runs offshore from about Eureka, CA, to Vancouver Island. Quite a bit of development in the tsunami zone there, although luckily Seattle/Tacoma and Portland are sheltered a good bit.
The truly scary part is that the historical period between major quakes on the CSZ is 200-500 years.
It's been 323 years since the last one, confirmed by tsunami records in Japan.
If memory serves, the CSZ was the focus of the pilot episode of the series "Megadisasters."