Can Android phones help predict earthquakes?

Cellphones alerted millions of Venezuelans about what was happening
Getty Images
The scene was repeated, with small differences, in homes, stores and businesses across Venezuela: an insistent alert sounded on cellphones, people looked at the screen and, after a brief moment of uncertainty, left the place in search of protection. Seconds later, everything began to shake.
This is how Google's earthquake warning system warned millions of Venezuelans using the Android operating system about the two earthquakes that hit the country on June 24 this year.
The alert was sent to 11.4 million people in Venezuela who, according to the giant technology company, had from a few seconds to up to two minutes to react before feeling the impact of the strong 7.2 magnitude earthquake. Seconds later, another tremor, with a magnitude of 7.5, hit the country.
As Venezuela does not have a national early warning system for this type of event, it is likely that Google's system helped prevent deaths and injuries.
But how does it work?
Millions of small seismometers
The alerts were sent through the Android alert system
Getty Images
In an article published in 2025, software engineer Marc Stogaitis explains how Google developed an early warning system for earthquakes (EEW) using measurements obtained by the global network of Android cell phones.
"The accelerometer of an Android cell phone, the same sensor that rotates the screen when the device is placed horizontally, can also detect the movement of the ground caused by an earthquake", explained Stogaitis in the text.
According to him, this sensor identifies the P wave, the first wave generated by an earthquake, and sends a signal to the detection server Google seismic.
As there are millions of Android cell phones around the world, the system gathers information sent by devices located in the affected area. Using this data, Google estimates the location, extent, and intensity of the tremors and then sends alerts to all Android devices in the affected region.
The advantage of measuring P waves is that they propagate faster and are less destructive than the secondary waves, also called S waves, generated by an earthquake. This allows you to gain precious time so that people can react.
The only requirement is that the cell phones that detect these waves are stationary.
According to Google, the objective of the system is to gather this information quickly and alert as many people as possible before the arrival of the S waves, which are the most destructive.
Two types of alert
What to do during an earthquake
BBC
The Android system only sends notifications when it registers earthquakes of magnitude equal to or greater than 4.5 and offers two types of alert:
Be aware (translated as "Be Aware of the Alert"), for lower intensity tremors.
Take Action (translated as "Action Alert"), when the estimate is for a stronger tremor. In these cases, the alert occupies the entire cell phone screen and is accompanied by an audible signal.
To receive the alerts, the cell phone must be connected to the internet, via mobile network or Wi-Fi, and have both the location and the earthquake warning system (EEW) activated.
According to Google, alerts of both types were sent during the two earthquakes in Venezuela. Around 1.4 million users received the most serious warning, with guidance to take protective measures.
In the 2025 article, the company reported that its earthquake warning system was available in around 100 countries. In many of them, such as Venezuela, there is no national earthquake warning system.
The system multiplied tenfold the number of people in the world with access to early earthquake warnings: from 250 million in 2019 to 2.5 billion in 2025, according to Google.
In February 2025, Google issued the same type of alert in Brazil, more specifically in São Paulo, Rio de Janeiro and southern Minas General. The warning located the epicenter of the tremor around 55 km from Ubatuba, on the coast of São Paulo, at sea. According to the message, the tremor would have a magnitude of up to 5.5.
But in the Brazilian case, there was no earthquake.
The Brazilian Seismographic Network (RSBR), coordinated by the National Observatory (ON/MCTI), as well as international seismic monitoring institutions, also did not detect any seismic event on the Brazilian coast during this period.
In a note at the time, Google stated that its earthquake warning system detected cell phone signals in a location close to the coast of São Paulo and triggered an earthquake alert to users in the region. "We promptly deactivated the alert system in Brazil and are investigating what happened. We apologize to our users for the inconvenience and remain committed to improving our tools," Google said in a statement.
Google highlighted that its alert system "was not designed to replace any other official alert system."
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Source: G1