In honor of Earthquake Preparedness Month in California, San Diego County's Office of Emergency Services reminded residents Wednesday not to get caught off guard and have a plan for how to protect themselves in the event of an earthquake.
The announcement followed a magnitude 3.5 earthquake that struck Borrego Springs early Wednesday and caused light shaking to be felt across the San Diego region.
The temblor struck shortly after 3:50 a.m. roughly 6.4 miles south of Borrego Springs, at a depth of about 4.3 miles, according to a computer-generated report from the U.S. Geological Survey.
Reports on the USGS "Did You Feel It?'' map showed light shaking could be felt across San Diego County, including in Poway, San Diego, Spring Valley, Lemon Grove, El Cajon, Alpine, and Jamul.
No damage or injuries were reported.
San Diego County is home to three major active faults: the Rose Canyon Fault -- which runs along the coast, through downtown, Old Town and La Jolla -- and the San Jacinto and Elsinore faults, which run through the northern and eastern areas of the county.
Significant earthquakes along these faults could disrupt roadways, transportation, and services like water, gas and phone communication for weeks or months. Coastal areas are also at risk for tsunamis.
As part of the state's 2021 "Don't Get Caught Off Guard'' campaign, county and state Office of Emergency Services officials are encouraging residents to update their emergency plan, register for local emergency alerts, and download an earthquake early warning app.
The county OES will release earthquake early warning technology, ShakeReadySD, in the SD Emergency app in July. When enabled, ShakeReadySD is designed to alert iPhone and Android users seconds before a magnitude 4.5 or higher earthquake with moderate to strong shaking is expected in an area so residents can take the right actions quickly to protect themselves.
In the meantime, Californians can download the state's free MyShake App to their iPhone and Android. Managed by Cal OES, the MyShake app is part of the Earthquake Warning California system that similarly uses a network of ground motion sensors located across the state to alert users through the app and the Wireless Emergency Alert system to "Drop, Cover and Hold On'' seconds before significant earthquakes arrive.
To register for AlertSanDiego, the county's regional emergency mass notification system, and to learn about steps to take to prepare for earthquakes and other disasters, visit the county's website.