This following on from a 6.4 a few days ago - another example of sequential earthquakes.

Dan, you did say the area was ripe for a big one

Yeah, the US west coast hasn't seen any major earthquake action in decades, and given the unusually high number of large quakes we saw around the rest of the 'ring of fire' over the last 12 months, it intuitively seems like CA is in for it, but of course that's not at all scientific.