Maybe an iffy source, but...

"Earthquake Warning for Northern California and Oregon"

'Following the recent significant earthquake off Eureka, California last week, there is a moderately higher probability of a much stronger quake along the San Andreas fault between San Francisco and Oregon in the next two weeks. According to Jack Coles, an earthquake forecaster, the recent series of quakes, including the 6.5 shaker off the Coast are possibly fore-shocks of something bigger yet to come.' Before it's news

I've never heard of Jack Coles

Sue