Get a heads up BEFORE the shaking reaches you

Earthquake Warning California is a program to alert people before shaking reaches them. It is the final step in the ShakeAlert® system that detects, analyzes, and disseminates information to give you a little time to DROP, COVER and HOLD ON and safely ride out the strongest shaking. 

ShakeAlert® and Earthquake Warning California is a partnership of the USGS, Berkeley Seismology Lab, Caltech, California Office of Emergency Services and other universities and agencies.

Earthquake warning california

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a graphic of seismic stations, connecting to a brain, connecting to cellphones

1. Detection

Seismic stations DETECT earthquakes. Seismic waves travel several miles every second. As soon as waves reach four or more stations, the PROCESSING Center is triggered.

2. Processing

The PROCESSING Center analyzes the seismic signals and estimates the location, magnitude and the area of strong shaking. If the magnitude and shaking strength are above a certain threshold, a ShakeAlert message is issued and sent to DELIVERY.

3. Delivery

The ShakeAlert messages are sent to YOU through the MyShake App. All Californians can download MyShake for iPhones or Android systems from your App store free of cost.

No one can predict earthquakes hours or days before they occur. Earthquake Warning California and ShakeAlert utilize technology to detect earthquakes AFTER fault rupture begins. The entire Detect, Process, and Delivery system is very fast, giving many people in the shaking area a few seconds of warning before the strongest seismic waves arrive. 

Not everyone will get the notification before the shaking starts. If you are within 10 or 15 miles of the epicenter, you may get the MyShake notice during or after the shaking.

Other delivery options are being developed, and you may receive a notification on your smartphone through Wireless Emergency Alerts or other Android services.

What should you do when you get a MyShake Alert?

Find a nearby desk or sturdy table to get under and hold on. You will only have a few seconds to find a safe spot to ride out the earthquake. After the shaking is over, you can contribute to citizen science by reporting your observations directly to the App.

You are the most important part of the Earthquake Warning California.

Your role is to understand what alerts mean and to DROP, COVER and HOLD ON and stay safe during the shaking.

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