A preliminary 3.6 magnitude earthquake struck Wednesday morning off the Northern California coast, according to the United States Geological Survey. The quake struck at 6:45 a.m. and was centered in the Pacific Ocean, about 53 miles southwest of Eureka in Humboldt County, the USGS said. The temblor was just the latest in a series of earthquakes shaking the same general region where a 7.0 magnitude shaker hit on Dec. 5 and triggered a rare tsunami warning. No other information was immediately available. Updates to come. Earthquakes Dec 5 Series of strong earthquakes in Northern California spark tsunami warning Earthquakes Dec 5 Tsunami warning canceled after strong California earthquake Earthquakes Dec 5 Strong NorCal earthquake is followed by dozens of aftershocks