What you should know about California's MyShake earthquake early warning system – Pasadena Star News

Given the unpredictable and destructive nature of earthquakes, a few extra seconds of warning can make a huge difference.

That's why the California Office of Emergency Services is reminding citizens to download the state's MyShake app, a free tool that provides earthquake alerts and warnings.

Developed by UC Berkeley in collaboration with ShakeAlert of the United States Geological Survey and Cal OES, the app is available for mobile devices on the Google Play Store and Apple App Store and allows residents to enter their home location and receive alerts when ground sensors detect significant shaking.

“This can mean critical seconds of lead time for earthquake preparation,” said Jon Gudel, a spokesman for Cal OES's earthquake early warning team. “Think of all the apps you have on your phone now. None of them could save your life, especially in Southern California with all the seismically active areas.”

The MyShake app is available in English, Spanish, Chinese, Vietnamese, Korean and Filipino and can be downloaded from smartphone app stores or directly from the MyShake website myshake.berkeley.edu/.

How earthquake early warning systems work

Earthquake-prone countries such as Mexico and Japan have long had earthquake early warning systems. With the introduction of the Earthquake Warning California System in 2019, California became the first state in the United States to offer a statewide early warning system.

The system works by collecting data from over 900 sensors located across the state that can detect earthquakes.

When an earthquake triggers the sensors, the data is sent to processing centers to locate the earthquake, determine the magnitude and estimated shaking. The MyShake app then sends an alert to smartphone users who have the app installed and are near the earthquake.

“An earthquake is a fault that usually occurs in two waves,” Gudel said. “The first wave moves faster and we use the data from that to transmit it to warning centers and then to users before the slower, more destructive second wave comes behind it.”

Residents would only be notified if the earthquake was magnitude 4.5 or higher, Gudel said.

How much time passes between the warning and the shaking?

For earthquake early warnings, the warning duration is seconds because the tools respond to events in real time.

“We cannot predict earthquakes, and the warnings we issue are not predictions,” Gudel said. “They are warnings.”

Therefore, the time between the warning and the feeling of the quake may vary depending on the person's location relative to the quake.

“The closer you are to the epicenter of an earthquake, the less time you have to prepare,” said Gudel. “If an earthquake hits a densely populated city center, the epicenter cannot receive the warning before the earthquake starts and you have no time to react.”

A magnitude 4.4 earthquake with its epicenter in Highland Park struck Southern California on Monday, August 12. It lasted several seconds and brought some violent shaking.

Kourtney Jensen, who lives in Glendale, said she was in the bathroom of her sixth-floor apartment when she received a MyShake notification on her phone.

“About 10 seconds later, the whole store was shaking and things were falling off the counter,” Jensen said. “It wasn't much of a warning, but it was better than nothing and at least I could prepare for it.”

Her roommate, who also had the app installed on her phone, was at work in Pasadena at the time of the quake and did not receive a notification until after the quakes had already begun.

Other ways to prepare for an earthquake

Earthquake preparedness is a common topic in California, but is often overlooked.

Gudel said it makes sense to have an emergency kit on hand that includes things like canned goods, fresh water and a first aid kit.

Some other quick ways to prepare are:

• Learn to use a fire extinguisher.
• Put together an emergency supply.
• Know how to turn off utilities.
• Establish local and national emergency contacts.
• Take first aid courses or community response team training.