Seems to me that Petra has her answer - There's probably possibility of immidiate triggering as in the Landers-Big Bear and Hector - Salton Sea sequence and then longer term triggering - like Landers-Hector.

I think of it like a table cloth - tie the corners and sides down over a table, then put a cut in the table cloth (representing the fault) and move it about 17 ft (relatively) and see what kind of folds and stresses are put on the other parts of the table cloth. It just has to effect other areas. (cause and effect)

Too bad we weren't keeping better records back in 1857 or we could see what kind of triggering might occur after a quake in that location.

Canie