Residents in Northern California were shaken by a magnitude-5.9 earthquake just after noon local time on Thursday. Following the recent significant earthquake off Eureka, California, there is a moderately higher probability of a much stronger quake along the San Andreas fault between San Francisco and Oregon. 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.