Chris,

This quake and it's close companion a few days ago sit in a volcanic fold from the ancient volcano that is in the Oakland Hills. Moraga and Orinda are about a mile apart.

However, this activity is not the norm around that area if memory serves me well and it is off the fault, which can indicate it may be the place that takes a little bit more of a leap in the not so distant future. That's the way one seismologist see's it, looking for events +/- 5 miles of a major fault line.

I guess time will tell.

Petra