I know it is quite strong, because it started slowly, and just kept building, until my house was rocking quite pronouncedly. That motion also means it is probably at least 100 miles away from South Orange County. I am going to guess a 7 as a wild guess.
The Google satellite map is real interesting. The irrigated portion of the Coachella Valley looks like a mountain ridge with trees until you zoom in.
If you go to a particular quake, there is an estimate of the locations where the quake would be felt, but it doesn't even show the coast San Diego/Tijuana.
