John, I don't have time now to go over Lowell's thesis. But, there is stuff in his work showing that quakes are triggered by the waves reflecting/refracting off the various layers. I'm not sure if this is all in his thesis. I'd suggest that you get his thesis,read it, and then contact him directly. I'm not even a seismologist, so my being an intermediary does not make sense-I just gave you enough to show that there could be something to it....Chris