At 10:57 p.m., the quake shook an area three miles north of The Geysers, according to the USGS.
The temblor had a depth of 1.4 miles and an epicenter located 12 miles east-northeast of Cloverdale, according to the USGS.
In the past seven days, two dozen earthquakes of magnitude 2.0 or larger have occurred around The Geysers, which is the largest single geothermal field in the world, according to the U.S. Department of Energy.
The region experiences constant micro-seismic events–earthquakes between 0.5 and 3.0 on the Richter scale–related to deep-well injection that the Department of Energy says is necessary for the extended and sustained production of geothermal resources at the site.
By contrast, 184 earthquakes with magnitude 1.0 or larger have occurred in the same time span.
The largest event recorded in The Geysers field was a magnitude 4.6 quake in 1973, according to the Department of Energy.
There are 22 active geothermal plants in the region that produce roughly 950 megawatts of power, or enough for about 950,000 homes.
Patricia Decker, Bay City News