How your Android phone can alert you about an earthquake (and how to enable it)

With recent earthquakes rattling cities like Delhi and tremors felt across North India, knowing a quake is coming, even a few seconds early, can be the difference between panic and action. Most Android smartphones already have a built-in system to alert you before the worst of the shaking hits. You just need to know how to turn it on.

How Android’s Earthquake alert system works

Your phone’s accelerometer, the same sensor that knows when you rotate the screen, can detect the early tremors of an earthquake, known as P-waves. These are fast but not…