I had heard the blast was 6:24pm.. but this could be it I Suppose.. It would show up on the automatic earthquake reporting - it doesn't mean it was a quake, but the sensors detected the blast and the seismologists can distinguish between them.

There is a link there to a map with fault names, and it looks to be on top of the san andreas - In looking at it on Google maps, it's about half a mile away from the fault.. easily within the fault zone I'd say..

Canie