According to the map at the web site scec.gps.caltech.edu:80/ftp/SCEC/maps/PhaseII.gif, there should be at least two earthquakes large enough to cause damage to old brick and stone buildings each century in Santa Barbara. That means that in the next ten years there is roughly a one in five chance of having an earthquake that big. I am afraid that that is about the best geologists can do now to predict earthquakes in Santa Barbara. There is almost zero possibility of a volcano forming in Santa Barbara any time in the next million years. I hope that doesn't disappoint you!