A preliminary 4.3 magnitude earthquake struck near Lake County in Northern California on Saturday morning, according to the United States Geological Survey. The quake, which struck at 7:30 a.m., was centered about 3.4 miles south-southwest of Cobb and 13.2 miles north-northwest of Healdsburg. The quake was followed by a preliminary 3.9 magnitude earthquake about a minute later in the same area.