An earthquake jolted The Geysers area Sunday, registering a magnitude of 3.4, according to the U.S. Geological Survey.
The 2:40 p.m. quake's epicenter was about two miles northwest of The Geysers and 13 miles southwest of Clearlake.
It had a depth of about two miles.
The Geysers straddles Sonoma and Lake counties and is the world's largest geothermal operation involving wells to remove steam and produce electricity.
The operation includes injecting ground water and wastewater from the Santa Rosa regional treatment facility deep into the ground to recharge the field. Geologists say the actions contribute to frequent earthquakes in the area.