It seems that the more “advanced” a society becomes, the shorter it’s memory. The Andaman Islanders did better in the 2004 quake than anyone else, and the previous big quake was hundreds of years prior. Native Americans not only have a memory of the last Cascadia earthquake 311 years ago, they have a memory of the explosion of Mt Mazama (Crater Lake) ~ 7600 years ago. We on the other hand can’t remember much that happened before Twitter and Facebook.
Modern societies intentionally discard anything old. So instead, we have to rely on science, not social memory for fill in what we have forgotten. Even in Japan, the stone tablets warning of past great tsunamis (see http://www.google.com/hostednews/ap/article/ALeqM5hnlFOddxHicXMy-m1x3Lnd5OfLtg?docId=3186d9e8c263410eb1c1e60efabc62b1) were ignored mostly, and even they were not old enough to record the even larger tsunamis of the past, as many of them were washed away by the recent one.
Subduction zone earthquakes may have recurrence times of 500-1000 years, so human memory is really of little use. In Cascadia, the 1700 AD earthquake was the most recent one, but not at all the largest. The largest event probably occurred ~ 5900 years ago, and may have been ~ three times the energy of 1700.