Federal officials have upgraded Friday's earthquake in The Geysers area to a magnitude of 3.7 from the initial 3.3.

The U.S. Geological Survey said the 2:30 a.m. quake was was centered about one mile north of The Geysers and five miles southwest of Cobb in Lake County.

The Geysers and surrounding communities frequently are shaken by small quakes, but in the last year a few have registered as high as 4.1.

On Sunday, a 3.2 quake was recorded at 11:16 a.m. about eight miles northeast of Point Arena in Mendocino County, according to the Geological Survey.