Billions of Phones Now Capable of Detecting Nearby Earthquakes

Fast Summary:

• Google’s Android Earthquake Alerts system uses billions of phone sensors to detect seismic activity and warn users about nearby earthquakes in real-time.
• Launched in 2020, the system enables 2.3 billion Android phone and smartwatch users worldwide to receive alerts, substantially more than the estimated 300 million people reached by other sources globally.
• Android devices act as mini-seismometers using accelerometers to measure vibrations. Alerts are sent for earthquakes with magnitudes of 4.5 or greater.
• Accuracy & limitations: While effective,the system does not detect all earthquake locations (e.g., mid-ocean ridges) due to coverage constraints.
• The detection algorithm has been locally refined to account for regional tectonic activity and varying device sensor sensitivities across countries.
• With alerts issued in 98 countries by default, Google targets regions with importent ancient seismic risk but lacking conventional warning systems; it supplements rather than replaces existing seismometer networks like shakealert or those from Japan’s Meteorological Society.
• Study findings include alerts successfully delivered for over 1279 seismic events as March 2024, with three false alarms attributed primarily to thunderstorms or unrelated vibration triggers.
• Two alert types exist: a “Take Action” warning urging immediate protection during strong shaking and a generic “Be Aware” notification providing earlier updates on potential weak tremors.

Images:

1. Early warnings helped mitigate risks before devastating quakes such as Indonesia’s deadly event in 2022 (Image credit: ADITYA AJI/AFP via Getty Images).
2. Android phones detected waves during Turkey’s magnitude-6.2 quake in April 2025 (Image credit: Data SIO et al.).