Hi Lowell,

Your post to is one that I will fondly remember. It just goes to show that each large or moderate earthquake leaves its mark in a special way. Though some things can be generalized, earthquakes like many other Earth related subjects are still individual with a signature of their own. A fingerprint, that says it comes from place zulu.

It seems the Chile earthquake you referenced shows that what one can survive does not rely entirely on magnitude alone. Much the same as the Alaskan 1964 earthquake, housing was a problem, but survival was much easier than one would have expected.

Roger mentioned amplitude and when I read that I had to wonder what will occur when our Rodgers Creek Fault finally lets go. Be it a 5.6 as occurred before near Santa Rosa the damage would still be substantial. If at the south end, it could bring a larger quake with less damage due to the surrounding farm land and fewer homes. However, if it ever does deliver a 6.7 to 7.0, then we here are in for a serious concern for that amplification situation.

This whole area here rests on an allevial plain. It was once marsh land and as the hills rose, silts from there deposited in the central low lying area. The heavy clay soil below can be sticky when wet and yet create large fissures when dry. The time of the year could also make a large difference in the outcome. It makes me wonder thinking along those lines if there would have been any difference if the Alaskan quake occurred during the rainy season, rather than the cold snow they had.

It really makes me see how broad and wide prediction will be in the end, but for each area of the planet, these soil conditions and building constuction will in the end determine how well one fares out between a 6.5 and a 9.7.

Petra