Between 2021 and 2024, Google’s Android Earthquake Alerts (AEA) system transformed over 2 billion Android smartphones and smartwatches into part of a global earthquake early-warning network. A recent study in the journal Science shows AEA performs comparably to traditional seismometer-based systems, reports Live Science.
The system uses accelerometers in idle, stationary Android devices to detect P-waves—the faster, less harmful tremors that precede damaging S-waves. When enough devices in an area detect P-wave signals, the system sends out alerts to users likely to experience shaking.
As of March 2024, AEA had detected more than 11,000 earthquakes and issued over 1,200 alerts in 98 countries. Coverage has grown from about 250 million people in 2019 to 2.5 billion people by 2024, thanks to this crowd-sourced detection method.
User feedback is strong: about 85% of users who experienced an earthquake reported receiving an alert, and 36% got the alert before the shaking began. False alarms are rare; just three in the studied period.
Although challenges remain. Estimating magnitude accurately for very large quakes is difficult. One example shows that during the Turkey quake in 2023, AEA underestimated its magnitude, leading to weaker alerts than optimal. Google has since refined its magnitude estimation algorithms.
Google emphasizes that AEA is intended to complement, not replace, formal seismometer-based warning systems. Its global scale and accessibility make it especially valuable in regions that lack dense seismic sensor infrastructure.