A 4.0-magnitude earthquake in Sonoma County was felt in Lake County yesterday morning. According to the US Geological Survey, the quake occurred at 11:50 a.m. and was centered 4.7 miles south of Cobb, 12.7 miles northeast of Healdsburg and 14.9 miles south-southwest of Clearlake. It was recorded at a depth of 1.2 miles.