Hi Roger. Thank you for the name. I found a lot of material by John Rundle, but most of it I can’t access, as I’m not a member, or I have to pay a fee.

I haven’t been able to find anything that would explain the answer to my question (s) at least not at this time, but I still have a lot of reading to do. However I did find something that I feel might prove to be more interesting to others. It may also provide me with a partial answer to some other questions I have been asking for sometime now.

Professor Rundle is a theoretical physicist working on problems both in the earth sciences, and more generically in the sciences of complexity. With joint faculty appointments in both Physics and Geological Sciences, he is a Fellow of CIRES, and is also currently Acting Director of the newly established Colorado Center for Chaos and Complexity located on the Boulder campus.

From what I have found so far indicates I have a couple of months of reading ahead of me. The following is part of what I have found so far. The last paragraph covers a thought that has been nagging me some years now. It doesn’t answer it, but it does indicate to me there is something there that is not understood. Take Care…Don in creepy town.

“The simple theory that everyone believes has it that the crack should go on forever,” says John Rundle, professor of geological science at the University of Colorado. “As it grows larger, its presence concentrates more stress on the crack’s tips, which drives it further on. So the question is, if you have a small earthquake, why doesn’t it grow into a magnitude 9 earthquake?” Magnitude 9 corresponds to the most powerful earthquakes on record (the Afghanistan quake was magnitude 6.9). The 1964 magnitude 9 earthquake that hit Alaska resulted in a crack in the Earth’s crust 1,000 km long. Such extreme occurrences are thankfully rare but, if current earthquake models are to be believed, they shouldn’t be.

The existing models assume that these stresses are uniform in the rock around the area of a crack, but Rundle and his colleagues have now called this into question. They made a different assumption: that there must be large variations in the stresses, and these variations hold the earthquake back.

“If a crack is growing in an area where the stress is high, then it’s going to grow easily,” Rundle says. “But if it goes through an area where the stress is low, it will slow down and maybe stop.” The researchers constructed a computer model to include these stress variations, and found that, for the first time, they could reproduce all the phenomena associated with real earthquakes.

Rundle and his colleagues can now model the effects of different types of fault, and produce the many types of earthquake that are seen in nature. The team is now applying its new tool to simulate earthquakes seen in the past. Recognizing the signature of an impending disaster may enable them to predict events up to six months in advance, Rundle says.

Both the Gutenberg-Richter and Omori aftershock-foreshock laws provide evidence that the dynamical processes responsible for earthquakes are not random, but instead indicate that some kind of nonlinear self-organizing physical processes are at work.