Photo by Gilles Lambert on Unsplash (illustrative)
On 17 July 2025, a team from Google published a study in Science on a global earthquake warning network built from ordinary Android phones. The motion sensors inside phones pick up the first, faster shaking of a quake, so alerts can reach people seconds before the stronger waves arrive.
Key facts
The system operates in 98 countries and has widened access to earthquake early warning from about 250 million people in 2019 to 2.5 billion.
Google says it has detected more than 18,000 earthquakes since April 2021, from magnitude 1.9 to 7.8, and sent 790 million alerts.
In a magnitude 6.7 quake in the Philippines in November 2023, about 2.5 million people were warned up to 15 seconds ahead.
Of 1.5 million people who answered a survey after alerts, 85% said they were very helpful.
Why it matters
The expensive seismic networks that warning systems rely on simply do not exist in many of the most earthquake-prone regions. A few seconds of notice is enough to get off a ladder, move away from danger and take cover.
Worth noting
Only Android phones receive the alerts, and coverage is weak over oceans and in thinly populated areas, where phones are scarce. Independent seismologists stress that public education is still needed so people know how to react.