When I was researching the Cascadia Subduction Zone about 15 years ago, I talked with Dr. Frank Gonzales of U. of Washington. He told me that geologists and seismologists had found beach sand as far inland as 11 miles up river channels on the Oregon and Washington coasts. The Indian tribes in the area have oral histories that describe how inland Indians went to the coast and found that the coastal villages and people were simply not there.
Dr. Gonzales said that (at that time) there were two working theories about the "big one" that was due; one was that the "big one" would be a magnitude 9 quake that would shake the region for up to 45 minutes, the other was what he described as "the decade from hell" in which the region would be wracked with mag. 8 quakes periodically for about a decade. Either way, it's potentially quite bad. It will make hurricane Katrina look like a tailgate party by comparison.
Thanks for the correction.
I read some more and learned being on the upper side of the subduction is no protection.
Merry Christmas.
It is obviously just a matter of time before the “big one” - and, if just based on the periods between previous events, we are due. I was talking to a environmental geologist and some others because they were laughing about some woman that has a car-topper on her van filled with emergency supplies. She lived in Redmond and works in Seattle. While she did seem a bit hysterical, I did comment that with those supplies, she might do a lot better than others that are stuck in Seattle for a week or more after the big one hits. Access into and out of Seattle is primarily over large bridges, which will only serve as artificial reefs for any rescue efforts.