SACRAMENTO, Calif. – Following a swarm of recent small magnitude earthquakes that began on Monday near the Salton Sea in Southern California, the Director of the Governor’s Office of Emergency Services reminded local emergency managers and the public to be prepared for the potential of similar or larger earthquakes over the next week.
“California is earthquake country. We must always be prepared and not let our guard down,” said Director Mark Ghilarducci. “The threat of an earthquake on the San Andreas Fault hasn’t gone away, so this is another important opportunity for us to revisit our emergency plans and learn what steps you need to take if a significant earthquake hits.”
This reminder comes just a few weeks before the Great Shakeout, a nationwide earthquake preparedness drill on October 20.
Ghilarducci asked the California Earthquake Prediction Evaluation Council (CEPEC) to convene on Tuesday morning to discuss and evaluate a sequence of small earthquakes that have occurred about 10 kilometers southwest of Bombay Beach, Salton Sea area. CEPEC is a committee of earthquake experts that reviews potentially credible earthquake forecasts and advises the Director using their best judgement.
The council concluded that stresses associated with this recent earthquake swarm may increase the probability an additional earthquake as large, or larger, than the September 26 magnitude 4.3 occurring over the next week (see footnote). They also recommended citizens should maintain a prudent level of earthquake preparedness. Ghilarducci also stressed that it’s always important for officials and the public to take steps to prepare.
On Tuesday afternoon, Cal OES held a conference call with emergency managers in eight Southern California counties to discuss this recent swarm of earthquakes and ensure that local emergency plans and preparedness education remains a priority. He reminded them of the important earthquake response and recovery planning work that has been done over the years, including earthquake plans in Northern and Southern California and the Cascadia Subduction Zone–Earthquake and Tsunami Plan along the north coast.
Footnote/Update (9/30/2016): This advisory was updated to clarify that CEPEC specifically evaluated the potential for the earthquake swarms to trigger a larger earthquake (M7.0+) on the San Andreas Fault. Scientists estimated values between 0.03 percent and 1.0 percent possibility of that happening. Click here for specifics of CEPEC evaluation.
Additional earthquake preparedness resources: