June 28 (UPI) -- A moderate earthquake struck in Northern California on Tuesday, an area that's highly vulnerable to seismic activity.
The U.S. Geological Survey said the 4.2-magnitude quake was measured near Cobb, which is located about 70 miles northwest of Sacramento.
The USGS said the quake was recorded before dawn on Tuesday at a depth of about a quarter-mile. It was initially measured at a magnitude of 3.8, but scientists later revised it to 4.2.
Earthquakes are common in much of California due partly to the San Andreas Fault, which begins in far Northern California and runs down to near the San Diego area. There are also other geological fault lines that affect the San Francisco Bay Area, such as the Rodgers Creek and Hayward faults.
Seismic instruments as far north as Redding and as far south as Coaling reported feeling Tuesday's quake.
There were no reports of serious injury or damage.