Since their first implementation in Mexico and Japan, earthquake early-warning (EEW) systems have provided critical advance notice of imminent earthquakes to countless people. Many seismic countries, however, still don’t have the infrastructure necessary to sustain such crucial networks, leaving their populations vulnerable to devastating earthquakes.
Researchers in the U.S. and Germany have tested a global earthquake detection and alert system that makes use of a device many people already own, including in less developed countries—Android smartphones. According to their study, published today in the journal Science, the Android Earthquake Alerts (AEA) system’s efficacy rivaled traditional seismic networks in its ability to detect seismic activity and deliver alerts.
“The global adoption of smartphone technology places sophisticated sensing and alerting capabilities in people’s hands, in both the wealthy and less-wealthy portions of the planet,” the researchers, including Richard Allen from the University of California in Berkeley’s Seismological Laboratory, wrote in the study. “Although the accelerometers in these phones are less sensitive than the permanent instrumentation used in traditional seismic networks, they can still detect the ground motions and building response in hazardous earthquakes.”
According to the study, 70% of the world’s smartphones are Android phones, which by default come with the aforementioned sensing and alerting capabilities. From 2021 to 2024, the AEA system detected an average of 312 earthquakes per month across 98 countries. The earthquakes had a magnitude between 1.9 and 7.8, and the system alerted users of earthquakes at or over a magnitude of 4.5, averaging around 60 events and 18 million alerts per month.
The AEA system also collected user feedback, revealing that 85% of users who received alerts experienced shaking, with 36% receiving the alert before, 28% during, and 23% after the shaking began.
When an earthquake occurs, different types of seismic waves radiate out from the epicenter. P waves are fast and weak, while S waves are slower and more destructive. Just like traditional earthquake detection systems, Android smartphones can detect both P and S waves. When a detection occurs, the smartphone sends the data, including an approximate location, to Google servers, which then search for the appropriate seismic source. Once they identify the source with sufficient confidence, the earthquake is announced and alerts are sent out.
So how can people receive an alert before they feel the shaking? The key is that electronic messages travel much faster than seismic waves, especially S waves. While people near the epicenter might not get any advanced warning, those living farther away will receive the alert before the seismic waves reach them—and even a few seconds could be just enough time to hide under a table or run outside.
“AEA demonstrates that globally distributed smartphones can be used to detect earthquakes and issue warnings at scale with an effectiveness comparable to established national systems,” the researchers wrote. “The goal of the system is to deliver useful and timely alerts in as many earthquake-prone regions around the globe as possible. The system is supplementary to any existing national warning systems.”
Despite the significant advancements scientists have made in identifying where earthquakes are most likely to occur, predicting when an earthquake will strike remains impossible, and seismic events continue to take lives all over the world.
“Large earthquakes remain the most important and challenging for all EEW systems, and the global implementation of AEA supports efforts to improve detection with rapid, large-scale data collection and feedback to algorithms,” the researchers explained.
The study goes to show that problems don’t always necessitate an expensive fix—sometimes the ingredients to a solution might already be in your pocket.
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