Another small earthquake jolted The Geysers early Tuesday, this one with a magnitude of 3.0, reported the U.S. Geological Survey.
It struck at 8:45 a.m. and was centered two miles northeast of The Geysers and four miles west of Cobb, in Lake County.
The quake had a depth of just over two miles.
On Monday, the Cobb area had a 2.6-magnitude shake.
The Geysers geothermal fields sit on the Sonoma and Lake county border.
The area experiences about 90 small earthquakes a month, attributed to the injection of wastewater and removal of steam to run power plants.
Most are in the 1.5-magnitude range, and the numbers have been steadily increasing for five years, according to U.S. Geological Survey officials.