As I understand it, the entire region is on a flat(well, tilted), planar fault because of the way the crust subducts. So you can have earthquakes anywhere in th

As I understand it, the entire region is on a flat(well, tilted), planar fault because of the way the crust subducts. So you can have earthquakes anywhere in the western PNW from that. But remember, the bay area is also home to many, many faults, and we don't even know the locations of them all. For instance, the next big bay area quake is likely to come from the Hayward Fault in the E. Bay.