Weather and pollution alerts on smartphones are pretty commonplace, but your Android phone can do much more. Google researchers have now shown the utility of Android phones as earthquake early warning (EEW) systems that can detect earthquakes globally and alert users in time before the ground starts to shake.
In a study titled, “Global earthquake detection and warning using Android phones“, published in the journal Science, researchers noted that the Android Earthquake Alerts system has detected thousands of quakes and alerted millions of people in nearly 100 countries. The system also learns from user feedback for improving key metrics such as magnitude estimation.
In order to detect possible seismic activity, Android makes use of the phone’s accelerometer. The accelerometer is a sensor that that detects linear acceleration and enables orientation detection/change and pedometer functions. Accelerometers work in conjunction with other components of the inertial measurement unit (IMU) in a smartphone that also include other micro-electromechanical systems (MEMS) such as the gyroscope and compass.
Earthquakes are broadly comprised of faster, non-destructive primary (P) and the slower, destructive secondary (S) waves. For earthquake alerts to work, an Android phone needs to be connected to Wi-Fi or a cellular network, with the Android Earthquake Alerts and location enabled in settings. This feature can be optionally turned off by the user.
When the accelerometer of a stationary Android phone first detects the P-wave, it pings Google’s earthquake detection server together with an approximated location. The location is coarsely identified in order to protect user privacy.
The server analyzes if other phones in that area are sending out similar signals and tries to estimate the quake’s location and magnitude. If so, it sends out alerts to all phones in that location. The idea is to alert users before the more powerful S wave strikes. The system sends out two kinds of alerts: Be Aware alerts for light tremors and Take Action alerts that take over the phone’s display and play a loud sound.
Essentially, each Android phone is now a tiny seismometer and together, all of them form a very effective EEW system. Owing to the significant proliferation of Android devices across the world, the number of people with access to EEW information is now a staggering 2.5 billion — a 10x increase from 2019 when people only had traditional EEWs to rely on.
The feature first started rolling out in 2021 in New Zealand and Greece and is now effective in 98 countries as of 2023. According to Google, the system has detected over 18,000 earthquakes from small M1.9 tremors to severe M7.8 ones. 790 million alerts were sent to phones worldwide for 2,000 significant quakes.
Google notes that estimating magnitude of an earthquake in real-time is a challenge, but the accuracy has improved over time to match or even better that of established major seismic networks.
Google even cites a few recent examples in the Philippines, Nepal, and Turkey, where the system proved its effectiveness. For instance, in the April 2025 Turkey earthquake that measured a 6.2 magnitude, the system posted the first alert in just 8 seconds after the quake began, sending over 16 million alerts and giving people a warning time of few to 20 seconds depending on their distance from the epicenter.
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Though a cell and molecular biologist by training, I have been drawn towards computers from a very young age ever since I got my first PC in 1998. My passion for technology grew quite exponentially with the times, and it has been an incredible experience from being a much solicited source for tech advice and troubleshooting among family and friends to joining Notebookcheck in 2017 as a professional tech journalist. Now, I am a Lead Editor at Notebookcheck covering news and reviews encompassing a wide gamut of the technology landscape for Indian and global audiences. When I am not hunting for the next big story or taking complex measurements for reviews, you can find me unwinding to a nice read, listening to some soulful music, or trying out a new game.