Thanks Bob,
I should add that I am not a scientist and took only minimum university science requirements MANY years ago. My major was history, and what interested me most about geology and seismology was how earth changes affected the progress of individuals and civilizations. After we moved from Kansas to California in 1960 and felt a few earthquakes, that interest became more personal. My husband couldn't discuss his work; what we learned from him was to be open to new ideas until they could be investigated. - Mary C.