Phones Sounded Before the Quake: Google's Earthquake Alert System

On June 24 (local time), Jose Flores, a resident of Caracas, Venezuela, received an earthquake alert on his Google Android phone while heading to a movie theater with his family.

Six seconds after the alert sounded on his phone, the ground began to shake violently.

The Google Android phone had detected the initial seismic waves and issued a warning before the earthquake struck.

In Venezuela, which lacks a national earthquake early warning system, a total of 11.4 million people received earthquake alerts on their Android phones up to two minutes before the powerful quake hit, the New York Times (NYT) reported on June 27 (local time).

Google's earthquake alert system operates by collecting data from more than 2 billion smartphones equipped with built-in accelerometers.

The system uses sensors that monitor screen rotation to detect minute vibrations and issues alerts for earthquakes with a magnitude of 4.5 or higher.

When an earthquake occurs, it first generates P-waves, which are fast but relatively weak, followed by stronger S-waves. Android smartphones detect the P-waves to measure the location and magnitude of the earthquake and send alerts to phones in the affected areas.

According to Marc Stogaitis, a principal engineer at Google, Android smartphones detected the P-waves of the first earthquake in Venezuela in three seconds and issued the first alert six seconds later.

The system subsequently detected the increasing magnitude of the earthquake and expanded the alert area.

The earthquakes in Venezuela were very powerful, with magnitudes of 7.2 and 7.5, and Google sent approximately 1.4 million alerts to residents in the areas that experienced the strongest shaking.

The NYT noted that while it is too early to determine whether these early warnings from Google Android saved lives during the Venezuela earthquake, even a few seconds could have been enough for people to take protective measures.

Flores, who received the alert in Caracas, said, "At first, I thought it was just because the road was bumpy, but when I saw the streetlights shaking, I realized it was a serious situation," adding that he would be better prepared if he received such an alert in the future.

"Receiving the alert is very helpful," he added. "It felt like it almost predicted the earthquake."

The NYT reported that approximately 70% of smartphones worldwide use the Google Android operating system, and according to a paper published in 2025, Google's earthquake detection system worked wherever smartphones were in use.

The powerful earthquake that occurred on June 24 has so far left more than 1,400 people dead and over 3,200 injured in Venezuela, with the number of missing persons approaching 70,000.
※ Please note: This article was translated by AI and may contain errors.