The City of Fontana has been experiencing a swarm of earthquakes since May, with more than 1,000 small quakes recorded in this short period of time.

It has been unnerving for many residents dealing with the daily anxiety surrounding the earthquakes.

In order to address the growing concerns that were expressed to myself and the City Council, the City of Fontana and San Bernardino County Fire Office of Emergency Services held a community meeting on June 27. This meeting included a panel of experts, along with a seismologist, to answer questions.

Dr. Elizabeth Cochran, a seismologist with the U.S. Geological Survey and the California Institute of Technology, explained that swarms of small magnitude earthquakes are common in the area from Riverside to Chino and can last from several months to a year.

She referenced November 1994 as the last time Fontana experienced a swarm with the largest event being a magnitude 3.4.

Dr. Cochran mentioned that based on historic recordings, this swarm called the “Fontana Seismicity Trend” is not expected to generate an earthquake stronger than a 4.0. Although highly unlikely, she did mention there are never any guarantees because the earth tends to do what it wants to do.

So, what is the “Fontana Trend?” According to Dr. Cochran, it is a network of small fractures and faults more than one mile deep below the surface.

There were concerns that perhaps the swarm was caused by construction in the area or because of the groundwater recharge process that allows water from the surface to percolate. Dr. Cochran explained that construction or water movement below the surface would not cause the earthquakes because the faults are too deep.

The U.S. Geological Survey can now detect much smaller magnitude earthquakes compared to several years ago because of improvements in technology. Extremely small quakes, such as a 0.5 magnitude, are now able to be recorded, which also contributes to the increased frequency in the “Fontana Trend.”

Most of the quakes have been under a magnitude 2. Dr. Cochran provided this website as a resource to view the seismic activity in the area: Of the 1,120 earthquakes, the largest was a magnitude 3.2 on June 2, five quakes were at least a magnitude 3.0, and 51 quakes were between magnitudes 2 and 3.

----- ALTHOUGH MOST of these earthquakes have been small, I cannot stress enough the importance of being prepared for larger earthquakes.

Staff from the Office of Emergency Services also provided residents with information about emergency preparedness. California is earthquake country, and these swarms serve as a reminder that we must do our part to prepare.

Emergency Services staff recommends developing a plan for your family or business. Consider how you will communicate, evacuate, and reunite during a disaster. Also, consider any specific needs you or those in your family may have. Develop a kit for yourself and those in your home or business. The public was also reminded to have enough food, water, and supplies to last at least 72 hours.

In the event of a major event, KFROG radio station 95.1 is the official carrier for the emergency alert system for San Bernardino County.

You can sign up for Emergency Alerts at You can also download the free San Bernardino County Ready App. The app is easy to download from your mobile device by simply going to

The app will help you prepare and plan for how to respond to a disaster in our area. The app features the following functions:

• Share your status with your selected contacts with the push of a button.

• Receive critical emergency alerts via push notification. 

• Locate San Bernardino County’s emergency shelters.

• View up-to-date evacuation route maps.

• Get the latest news and weather for the San Bernardino County area. 

• Create a personalized Emergency Preparedness Plan by answering five basic questions. 

Once Your Plan is generated, it is stored on your smartphone and can easily be shared with family members and friends. Your Plan is made up of:

• An Emergency Supply Kit Checklist tailored to your needs.

• A Customized Emergency Food Supply Shopping List.

• An Emergency Communications Plan to notify your loved ones of your status.

• Critical information to prepare your home for a disaster.

When it comes to earthquakes and all other disasters, we are in this together as a community. Our public safety professionals and city staff are always training and doing what they can to keep you safe.

Let’s do our part and take care of our families and neighbors by ensuring we have taken the proper steps to develop a disaster plan.

If you are interested in more earthquake and emergency preparedness resources, please visit the websites provided. Until next time, be safe and plan ahead.

Resources shared at the meeting:

(Acquanetta Warren is the mayor of Fontana.)

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