Google has confirmed that its Android Earthquake Alerts System detected seismic activity in Venezuela and pushed warning notifications to users moments before the earthquakes hit the country.
The system, embedded in most Android phones, has been issuing earthquake warnings across dozens of countries since 2020. A Google-funded study published in the journal Science found that its detection and warning capability is comparable to that of established national seismic networks.
How the detection works
A Google official confirmed to HT that they had indeed sent out alerts to affected Android users in Venezuela. Android uses two separate methods to spot earthquakes. In California, Oregon, and Washington, Google works with the US ShakeAlert system, which draws on more than 1,600 ground sensors to pinpoint an earthquake's location and magnitude before relaying the data to Android devices.
In the rest of the world, detection is crowdsourced. Each smartphone's built-in accelerometer can pick up vibrations, and when a phone senses movement resembling an earthquake, it relays a signal and rough location to Google's servers. The system then cross-checks data from numerous nearby phones to confirm whether a quake is actually underway, effectively turning a vast pool of Android devices into an informal seismic sensor network.
Two tiers of alerts
Warnings are issued only for earthquakes of magnitude 4.5 and above, split into two categories. A 'Be Aware' alert, meant for users likely to feel only mild shaking, functions like a standard notification and follows the phone's existing sound and 'do not disturb' settings. A 'Take Action' alert, by contrast, is reserved for users expected to feel moderate to severe shaking. It bypasses device settings, lights up the screen, and plays a loud alarm. Both alerts open to a safety guide along with a map showing an early estimate of the quake's epicentre and strength.
Because the warnings travel as electronic signals, they can outrun the slower seismic waves themselves, giving people a short window, often just seconds, to take cover, Google has said.
Track record and scale
Google has cited a November 2023 earthquake in the Philippines, magnitude 6.7, where its system issued the first alert within roughly 18 seconds of the tremors beginning. Users nearest the epicentre got up to 15 seconds of advance warning, while those farther away received up to a minute; nearly 2.5 million people were alerted in total.
The system launched in the US in 2020 via the ShakeAlert partnership and began rolling out independent, crowdsourced alerts in April 2021, starting with New Zealand and Greece. It now operates in 98 countries, including India, and is designed to supplement, not replace, official government alert systems.
The Science study, which reviewed three years of the system's operation, found it detects an average of 312 earthquakes a month globally, with alerts going out for around 60 events of magnitude 4.5 or higher each month, reaching close to 18 million phones. Among surveyed users who received an alert, 85 per cent said they actually felt the tremors, with more than a third of them getting the warning before the shaking began.
