Google has built a new algorithm that can use standard Android phones to detect and warn of earthquakes. In this way, Google creates a network of millions of "mini-seismographs" around the world .
The service, which the user must turn on, uses the mobile's built-in accelerometer to detect shaking. The algorithm then analyzes data from all mobiles using the service to see if there is an earthquake.
If there is an earthquake, an alert is automatically sent to everyone in the area. As a few seconds' warning can be the difference between life and death in the event of an earthquake, the new service will hopefully be able to save many lives in the future.