Chris,

However, this is getting interesting: " you would be one of the seismologists who would have said nonsense to distant P and S wave triggering". Are you suggesting I did say that, or that I am of that ilk?

By the way, the triggering from Landers, Hector Mine, and Alaska is most likely from the surface waves, not from the P and S body waves.

We looked at the triggered seismicity at Mammoth Mts from 7 different earthquakes at lunch; Emily Brodsky here at UCLA is isolating the frequency-dependence of the triggering in the attempt to determine its mechanism. It seems to be the 10+ s period energy that does the damage.

My thesis in this thread is that at least several of the distances of the rings do not involve significant amplification of the peak ground motions, and I am asking whether there is evidence to contradiction this opinion. I'll have our librarian chase down the Lowell's thesis to see.

John