Sunday afternoon, residents of the San Francisco Bay Area checked to see if they had, in fact, felt the ground shake beneath them after three seismic events — which were later followed by another four smaller earthquakes later in the day.
Earlier today, December 14th, a trifecta of earthquakes rattled neighborhoods near Santa Rosa, with some reporting noticeable shaking as far away as Vallejo. These three tremors were later followed by a pair of smaller earthquakes, each of which was registered in the same area as the former earthquakes.
Good afternoon Northern California! Did you feel the magnitude 4.2 quake 4 miles west of Glen Ellen at 3:30 pm? The #ShakeAlert system was activated. See: https://t.co/wcWCyLrOUo @Cal_OES @CAGeoSurvey @USGS_Quakes pic.twitter.com/ecrJ5S5npI
— USGS ShakeAlert (@USGS_ShakeAlert) December 14, 2025
According to the United States Geological Survey (USGS), a series of three earthquakes — the first being the largest at 4.0 magnitude and epicenter in Glen Ellen; the subsequent pair registered over 3.0 magnitude in strength and are believed to be aftershocks — struck the quiet rural areas between Jack London Historic State Park and Trionne-Annadale State Park, starting around 3:30 pm.
The three earthquakes were recorded at strengths of 4.0 magnitude, 3.1 magnitude, and 3.4 magnitude, respectively, and in chronological order. This evening, a 2.5 magnitude and 2.6 magnitude earthquake, likely aftershocks, followed today’s earlier tremors.
All five tremors registered epicenters smack dab on the Rodger Creek Fault — one of the region’s most at-risk fault lines capable of producing a 6.0m or greater earthquake within the next 20 years. Moreover: The Rodger Creek and Hayward Faults, which geologists believe are direly connected underneath the San Pablo Bay, have a 33% combined chance of producing the next “big one”; the infamous Hollywood-propagandized San Andreas Fault only has roughly a 7% of creating the SF Bay Area’s next life-changing earthquake.
Shakemaps provided by USGS show jerks from three of today’s five tremors produced “light” previous shakes within about 10 miles of their epicenters, with today’s 3.4 magnitude quake epicentered in Kentwood, only a few miles from the two others recorded in Glen Ellen. The 4.3m magnitude earthquake produced the day’s strongest activity with “weak” shaking felt as far away as San Francisco, with small incidents down the Peninsula.
Two more small earthquakes, a 2.7 magnitude and 2.8 magnitude, struck near San Ramon Sunday evening along the region’s lesser-known Calaveras Fault; the fault system produced the SF Bay Area’s strongest earthquake in years — a 5.1 magnitude tremor centered near San Jose on October 25th, 2022.
