California’s First-In-The-Nation Earthquake Warning System Notified 2.2 Million People of Bay Area Quake


SACRAMENTO – Continuing to lead the country in emergency management and disaster preparedness, California’s first-in-the-nation Earthquake Early Warning System, implemented under Governor Gavin Newsom’s leadership, provided advanced notification to more than 2.2 million Californians before shaking started for the 5.1 magnitude earthquake that was felt throughout the Bay Area Tuesday.

These advanced notifications provided up to 19 seconds, in many locations, for Californians to take protective action to “drop, cover, and hold on” and stay safe during the earthquake. An estimated 2.1 million Android users received the notification directly on their phone without needing an additional app because the state’s partnership with Google incorporates the technology on all Android smartphones, in addition to more than 95,000 MyShake App users who also received the warning.

“California continues to harness the power of science and technology to help keep our communities safe. When it comes to earthquakes, seconds can save lives. That’s why California continues to invest in new and emerging technologies to protect the most vulnerable among us,” said Governor Newsom.

There were no reports of significant damage or injuries related to the earthquake, whose epicenter was in the community of Seven Trees and was felt across large portions of Northern California. The Governor’s Office of Emergency Services (Cal OES), which manages the earthquake warning system on behalf of the state, continues to coordinate closely with local officials in the impacted region to evaluate any issues or unmet needs. Due to the success of Tuesday’s performance, the Earthquake Early Warning System saw more than 108,000 new downloads of the MyShake App in a single day, a record.

In addition to the emergency alerts sent to individuals through MyShake and Android, the underlying technology is also being used to automate protective actions such as slowing trains, opening firehouse doors, recalling elevators, shutting off water and gas valves as well as closing bridges gates and notifying personnel in school and medical settings.

“While California has faced fires, drought and even a global pandemic, the single biggest threat we face to life and property in our state is a sizeable earthquake in one of our major population centers,” said Cal OES Director Mark Ghilarducci. “Tuesday was another important step in testing our technology but work still remains to prepare for the next big one.”

Warnings delivered through the system are based on a computerized program called ShakeAlert, operated by the United States Geological Survey (USGS) in partnership with Cal OES that analyzes data from seismic networks in California, calculates preliminary magnitudes, and then estimates which areas will feel shaking.

In 2019, on the 30th anniversary of the deadly Loma Prieta earthquake, Governor Newsom announced the launch of the nation’s first statewide Earthquake Early Warning System.

The California Earthquake Early Warning System marries a smartphone application with traditional alert and warning delivery methods such as Wireless Emergency Alerts (WEA). The system uses ground motion sensors from across the state to detect earthquakes before humans can feel them.

Building on this success of the Governor’s 2019 launch, in 2020 Governor Newsom announced a partnership with Google to incorporate California’s earthquake early warning technology into all Android smartphones.

To date, more than two million users have downloaded California’s MyShake App.

To learn more about earthquake preparedness and download the earthquake early warning application, visit:


How to Receive Alerts

To receive earthquake warnings, there are three ways for individuals and families to get alerts through the Earthquake Warning California system.

  • MyShake App: Free smartphone app that provides iPhone users with audio and visual warnings, available in both English and Spanish.
  • Android Earthquake Alerts: Android phones with updated operating systems are automatically subscribed to Android Earthquake Alerts, which uses the same technology as the MyShake App; and
  • Wireless Emergency Alerts (WEAs): No-cost text messages for emergency situations sent through the nation-wide system providing lifesaving information for the State of California

HomeBase Feature

The MyShake app launched its newest enhancement called HomeBase in 2022. This feature allows users to set a default location where they can receive earthquake early warning alerts, even if location services are temporarily down or turned off.

This will increase MyShake’s ability to send timely alerts so that Californians affected by an earthquake can receive warnings at a location of their choosing and be prepared for shaking.

To activate the HomeBase function, users should update their MyShake app and navigate to the Settings page, where they will find an “Add HomeBase Location” button.

The HomeBase feature differs from a function already in the app where users can receive earthquake notifications for other locations, even in other countries. For example, if users want to receive notifications for earthquakes that occur where family or friends live, they can add those locations under Settings > Notifications.