The quake, originally stated as being a magnitude 4, occurred at 10:27 a.m. at a depth of 2.5 miles, according to the US Geological Survey.
It was centered one mile northeast of The Geysers, four miles west southwest of Cobb and six miles west northwest of Anderson Springs, the US Geological Survey reported.
The Anderson Springs strong ground motion station reported that the quake registered 6.9 percent of a g – an acceleration measurement – while it rated 6.4 percent of a g at the Cobb station, according to Jeff Gospe, president of the Anderson Springs Community Alliance. Those measurements are about three times the acceleration experienced on a roller coast, the US Geological Survey reported.
The quake was a V on the Modified Mercalli Intensity scale, said Gospe.
That rating is explained as “Felt by nearly everyone; many awakened. Some dishes, windows broken. unstable objects overturned. Pendulum clocks may stop,” according to the US Geological Survey description.
Residents of Lake, Sonoma and Napa counties reported to the US Geological Survey that they felt the quake, which was even felt as far away as San Francisco and San Jose.
Cobb resident Roger Kinney said the quake started as a large boom, with the shaking moving toward his home.
The Geysers area had a 3.0-magnitude quake on June 22, as Lake County News has reported.
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