5 days ago
- Science
- San Francisco Chronicle
Magnitude 3.2 earthquake strikes near Concord
A preliminary magnitude 3.2 earthquake shook the Concord area shortly after noon on Friday, according to the United States Geological Survey.
The earthquake was centered just over a half mile south of the East Bay city. Light shaking was reported in parts of the Bay Area.
There were no immediate reports of damage.
While the quake was minor, it occurred in a seismically active region along the Concord-Green Valley Fault system.
The right-lateral strike-slip fault system experiences a steady creep of up to 5 mm per year, and has been linked through complex fault interactions to nearby faults, including the Mount Diablo Thrust and the northern Calaveras Fault, according to the USGS.
The last major surface-rupturing earthquake on the Concord-Green Valley Fault is estimated to have occurred between 200 and 500 years ago.
According to the 2003 Working Group on California Earthquake Probabilities, there is a 4% chance that the fault system could produce a magnitude 6.7 or greater earthquake within the next 30 years.
