Since I live in an active seismic zone, I'm a tad sensitive to the rumblings beneath me. Also, I live next to an active artillery range, aka Fort Lewis, aka JBLM, which might be known to y'all as the home base of them fighter jets that tailed Danny Boy a few years back, as in McChord Air Field. So, I feel things almost nightly.
We here live a few miles east of the Cascadian Subduction Zone, which slips every 350 years, on average. When it goes, it goes big - a minimum of an 8.0. Last one was January 1699, I believe, based upon the Imperial Records of the Court of Japan, which noted a huge but mysterious tsunami, courtesy of our earthquake. So, we're a bit overdue. The Cascadian has slipped a few dozen times in the current geological epoch.
Rule of thumb - if the shaking lasts four minutes, that's an 8.0. But five-six minutes puts you in the 9-10 range. So far, the worst I've seen is a couple of minutes - a 7.2 back about 15 years ago, known as the Nisqually Quake.
We have drills every year to deal with these possibilities. If and when we get the Big One, everything west of I-5 is toast. Seattle and Tacoma will survive, but will be uninhabitable. Authorities are estimating that the Cascadian quake will destroy at least half of all building stock from Portland to Vancouver, BC, including hospitals, police stations, firehouses, etc. All infrastructure will be rendered useless, such as fuel pipelines, sewage, water lines, etc. All roads will be impassable due to the collapse of bridges and over-passes, etc.
Rebuilding the Pacific Northwest to anything close to modern standards is estimated to take at least 20-30 years, depending on the availability of resources from outside the area, such as you folks in Florida, Iowa, and Tennessee. So please keep paying your taxes down there, and we all up here thank you, in advance.
But we'll have some great stories to tell when we show up to visit!
