3.0 EARTHQUAKE HITS SOUTHWEST OF COBB

A magnitude 3.0 earthquake rattled The Geysers area Sunday morning.

The quake struck at 9:42 a.m. and was centered 2 miles northeast of The Geysers and about four miles southwest of Cobb in Lake County, according to the U.S. Geological Survey.

The Geysers straddles Sonoma and Lake counties and is the world's largest geothermal operation where wells remove steam to produce enough electricity at 22 power plants to serve 750,000 homes. 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.

The vast majority of quakes are tiny, registering in the 1.0 and 2.0 range. But an increasing number in recent years have been a 3.0 or higher, according to the USGS.

-- Randi Rossmann