Recent earthquakes in Venezuela and Colombia have highlighted how mobile phones can provide potentially life-saving warnings before or during seismic activity.
Venezuela experienced two powerful earthquakes on June 24, measuring magnitudes 7.5 and 7.2, according to the Venezuelan Foundation for Seismological Research. On August 10, Colombia recorded a magnitude 7.4 earthquake near San José del Palmar in Chocó, the Colombian Geological Service reported.
Some mobile phones can automatically display an earthquake warning, but the system works differently on Android devices and iPhones.
Google operates its own Android Earthquake Alerts System, although availability varies by country. Apple’s enhanced earthquake warning service is currently limited to the United States and Taiwan. Elsewhere, iPhones generally depend on emergency notifications issued by governments and transmitted through participating mobile networks.
Activating Earthquake Alerts on Android
Google says earthquake alerts are normally switched on automatically on compatible Android phones. Users can check the setting by following these steps:
- Open Settings.
- Select Safety and emergency.
- Tap Earthquake alerts.
- Make sure the option is enabled.
On some phones, the setting may be found under Settings > Location > Advanced > Earthquake alerts.
The phone must have Wi-Fi or mobile data enabled to receive notifications. Google also uses the device’s approximate location to decide whether an alert should be sent.
The Android system can issue warnings for nearby earthquakes with a magnitude of 4.5 or greater. However, not everyone in the affected country will necessarily receive one. Notifications are based on the phone’s location and the intensity of shaking expected in that area.
Warnings are not guaranteed to arrive before the earthquake begins. Depending on the user’s distance from the epicentre and how quickly the event is detected, an alert may appear before, during or after the initial shaking.
How Android Detects Earthquakes
Google uses Android phones as a large-scale earthquake detection network. Smartphones contain accelerometers capable of identifying vibrations.
When several devices in the same area detect movement consistent with an earthquake, they send signals and approximate location information to Google’s servers. The data is analysed to estimate the earthquake’s location and likely magnitude.
Because information travels online much faster than seismic waves move through the ground, people farther from the epicentre may receive several seconds’ warning before the strongest shaking reaches them.
Activating Emergency Alerts on an iPhone
Apple does not currently offer its enhanced earthquake alert system in Colombia, Venezuela or many other countries. Its dedicated system is available in the United States and Taiwan on supported versions of iOS.
Elsewhere, iPhone users may receive government emergency warnings if local authorities issue them and their mobile operator supports the service.
To check the settings:
- Open Settings.
- Select Notifications.
- Scroll to the bottom of the screen.
- Find Government Alerts.
- Ensure the available emergency alert categories are enabled.
Apple says government alerts are normally activated by default. Availability depends on the country, region, SIM or eSIM and mobile operator. In some places, certain emergency notifications cannot be switched off.
Enabling Government Alerts on an iPhone is therefore not the same as activating Google’s Android earthquake system. An iPhone warning can only be received where an appropriate public alert service exists and the mobile network supports it.
