Manda,
Be prepared for the response from Don. He can tell you the seismic history of your mailbox! I've never ceased to be impressed by his wealth of knowledge.

As for me, I think the crust is very brittle in the area's you mention, and wouldn't be surprised if a large quake were to strike at any time. The question is not if; It's when. Try to stay prepared, and check out earthquake prep advice on the web, esp. Petra's site at http://www.theseismicsafetyzone.com/

Take care, Billion
http://www.billionwatts.com