If I recall, real estate prices dropped for about a year in the LA area after the Northridge earthquakes. I personally know two families who took advantage to purchase from freaked out people who decided the sunshine was not worth the earth quake risk and moved back to wherever they were from. One was in OC, one was in the Valley. Admittedly, this is anectdotal evidence.
It’s hard to say how much of the home price decline was due to the earthquake – there was a dip in housing prices during the same window for economic reasons. But the persons I know had been looking, and felt it was the time to get a bargain.