Roger,

I was going on general impressions from time past. Seems like we had quakes about once a month back then. So your figures look about right. Maybe shes going to cut loose again. No way to know with out more paleo-evidence of any kind of cycle to it. I don't think a seismic cycle would be evenly spaced time wise anyway. There's no proof to that without 10,000 years (or more)of data.

Glen