Hi Dennis. I think part of the problem is that there just isn’t enough information on past earthquakes for a given area. Of course this method is statistical prediction. One tries to judge the future by what has happened in the past.

Scientists study the past frequency of large earthquakes in order to determine the future likelihood of similar large shocks. For example, if a region has experienced four magnitude 7 or larger earthquakes during 200 years of recorded history, and if these shocks occurred randomly in time, then scientists would assign a 50 percent probability (that is, just as likely to happen as not to happen) to the occurrence of another magnitude 7 or larger quake in the region during the next 50 years.

But in many places, the assumption of random occurrence with time may not be true, because when strain is released along one part of the fault system, it may actually increase on another part., Four magnitude 6.8 or larger earthquakes and many magnitude 6 - 6.5 shocks occurred in the San Francisco Bay region during the 75 years between 1836 and 1911. For the next 68 years (until 1979), no earthquakes of magnitude 6 or larger occurred in the region. Beginning with a magnitude 6.0 shock in 1979, the earthquake activity in the region increased dramatically; between 1979 and 1989, there were four magnitude 6 or greater earthquakes, including the magnitude 7.1 Loma Prieta earthquake. This clustering of earthquakes leads scientists to estimate that the probability of a magnitude 6.8 or larger earthquake occurring during the next 30 years in the San Francisco Bay region is about 67 percent (twice as likely as not). Of the faults in the Bay Area the one chosen as the best candidate for a large quake is Rodgers Creek Fault.

How many large earthquakes where there in the Bay Area before 1836? How long, or how short were the periods between the large earthquakes? I feel that one day there will be a method for predicting earthquakes, but as to how accurate it will be I can’t say. I also feel that there will be areas in which there will be no way of predicting an earthquake. A good example of this is the New Madrid quakes in 1811 and 1812. How many years before these quakes were there other large earthquakes?

I to would like to know how they are going to be able to prove it. The fact that at present time there is no reliable way of predicting a major quake could be said to be proof that it can’t be done, but does that mean there will never be a way of predicting a major quake?

A lot of questions are being asked, but not many answers are being given. Take Care…Don in creepy town.