Hi All. This is from a study done in 1989 so it is kind of dated, but at present time I have found very much that would change anything discovered during that study.

“If a major quake struck along the Rodgers Creek fault, "the whole North Bay area would really suffer a lot of damage," says geologist David P. Schwartz. The fault is half as far from San Francisco as the branch of the San Andreas that spawned the magnitude 7.1 Loma Prieta earthquake on Oct. 17.”

“The researchers remain unsure of when the fault last broke. While records indicate an earthquake hit the North Bay area in 1808, geologists cannot determine whether it originated on Rodgers Creek or a nearby fault. Schwartz concludes Rodgers Creek has remained quiet for at least 181 years, perhaps much longer, and thus could break soon.”

“Other evidence supports the idea that the fault is storing energy for a quake. Seismologic records reveal it has not produced many "micro earthquakes" in the past two decades. In addition, the opposite sides of the fault are not creeping past each other. This suggests they have locked together and strain will continue to build until an earthquake breaks the fault.”

This area is located between Petaluma and Wildcat Mountain. In December of 1981 there was a quake swarm near the northern end of the quiet zone. I was told by a couple of seismologist to watch for quakes less then 8Km east of the fault. The quakes could be in the moderate range similar to the ones that occurred before the 1989 Loma Prieta quake. It took me a little while to figure out what they were talking about. The two quakes that occurred before the Loma Prieta didn’t increase the strain on the fault in the area of the quake, but it instead reduced the strain, which in turn allowed the fault to move which in turn gave us the Loma Prieta quake. Sounds real simple, but somehow I don’t think it is that simple. It seems when it comes to earthquakes nothing is ever simple. Take Care…Don in creepy town

Rodgers Creek fault

Hayward fault trench

Stress transfer