Hi Cathryn, Roger, Russel et al. - I don't think I would be quite so sanguine about the "where." We only tend to think we have a handle on that, but it is all in the theoretical sense. As evidence, I submit the fact that not one single major quake in the United States, with the lone exception of Loma Prieta, has ever occurred in a location where we were looking for one!

Marc's clever and funny reference to Schroedinger's Cat actually is quite apt. In additon to quakes and subatomic particles both having properties that can only be determined singularly, the mere act of observation, or measurement, appears to alter the facts. Seismicity is also very much like the stock market. One can frequently, using past data, recognize a pattern - one which seems like it will be quite useful. But as soon as that pattern is applied, it fails. Mogi doughnuts, once so promising, are now almost completely discredited, and seismic gap theory, taken for granted by so many, is also still very controversial. In any event, it hasn't been of much use. I do not mean to have my comparison of quakes and subatomic particles taken literally, but I do find Marc's observation interesting.

And, Cathryn, you write "If everyone would pool their data, some really valid predictions might ensue." Hundreds of the best, brightest, most dedicated and motivated seismologists have been doing exactly that for decades with extremely limited success. Lest anyone really believe another poster's contention that scientists are all in direct, hostile competition with each other, and that they hide their work and data, I suggest a trip to a University library to read the professional publications. Within those publications, and at their meetings, and in their own numerous private channels of communication, a very efficient form of information sharing goes on. And this extends to the incredibly open and extensive volumes of global, raw data, from seismic networkds, GPS systems, and on and on. For both current and past events.

Finally, just in case anyone might not have noticed, the fault map Roger provided is clickable. That is, you can click through to the close, regional view, and then, clicking on one of the faults brings up information on that particular fault.

Michael Williams in Arroyo Grande, CA