I work for the California Geological Survey. Our office is at the U.S. Geological Survey's Menlo Park campus.

Freqency of earthquakes has not altered much. There are continual predictions of upcoming earthquakes by many groups. So far they have all proved wrong. The reality is that a major earthquake will occur at some point. There is no scientific way to predict earthquakes. The best thing is to be as prepared as you can be.

For more information on earthquakes in California, here are links to both the U.S. Geological Survey and the California Geological Survey:

USGS Earthquakes Hazards Program

California Geological Survey