2010 Eureka earthquake occurred on January 9 at 4:27:38 pm PST offshore of Humboldt County , California , United States . The magnitude was measured 6.5 on the scale , and its epicenter was located offshore in the Pacific Ocean west of the nearest major city , Eureka . Additionally , there was a separate earthquake further offshore of Eureka on February 4 with a slightly lower magnitude of 5.9 . It was also the most significant earthquake in the Eureka area in terms of magnitude since the 1992 Cape Mendocino earthquakes . It was felt from Santa Cruz County , California in the south , to Eugene , Oregon in the north and to the east as far as Reno , Nevada
1992 Cape Mendocino earthquakes
1992 Cape Mendocino earthquakes
2010 Eureka earthquake