Earthquakes aren’t uncommon for Californians.
“It's common," said Shell Beach resident Kathie Merlo. I've felt them here. I felt them in San Diego."
A 5.1-magnitude earthquake struck near Ojai in Ventura County just days ago, serving as a reminder about the importance of prevention before a disaster.
“We have family in Ventura and the earthquake was in Ojai, so I called them this weekend," added Merlo.
Earthquake alerts went off to some people in Santa Barbara County where the Office of Emergency Management reported it was also felt.
The "My Shake" app alerted many of those individuals to the quake.
It's a free app that gives people seconds of advance notice before the shaking strikes.
According to the California Governor's Office of Emergency Services, or Cal OES, Earthquake Warning California utilizes the California Integrated Seismic Network. The system uses ground-motion sensors to detect earthquakes that have already started and estimate their size, location, and impact.
“What it's designed to do is to give you, in theory, a pre-warning of an earthquake. There are sensors throughout the whole state," said Scott Jalbert, director of SLO County Office of Emergency Services.
When it detects a magnitude of 4.5 or higher, the system issues a "shake alert" message on your smartphone providing a warning before shaking begins.
“When that is activated, it only gives you a couple of seconds, but those two or three seconds could save your life," added Jalbert.
During an earthquake, there are three different types of waves. P-waves are the first to arrive but the damage is caused by S-waves and surface waves.
State sensors detect the P-waves and transmit the data to users
The My Shake app is free to download on iPhones and Android.
To learn more you can visit this website.