A preliminary 4.2 magnitude earthquake struck Tuesday morning near Cobb, California, according to the United States Geological Survey.
The quake, which hit at 4:57 a.m., was centered about 1.5 miles northwest of Cobb and about 16 miles northeast of Healdsburg, the USGS said.
The temblor initially was measured at a 3.8 magnitude, but the USGS revised it to 4.2.
No other information was immediately available. Updates to come.