Following a little on something Todd said below, I'll point out the couple little quakes between Oxnard and Ventura. The largest is only M2.1. This is a place to watch....on through the west end of the Northridge rupture. It is the same S-dipping fault system, even if it is usually not considered the same fault. Slip rates are as high as 5 mm/yr near Fillmore (mostly vertical), and it has been more than 200 years since the last big quake on this section. Let's see, that would be a meter of stored slip...., or maybe much more if it has been much longer. One of many hazardous places in California....and with the small cities/towns Ventura, Santa Paula, and Fillmore built on a really deep sedimentary basin........Chris