July 2025

Android based algorithms can detect early seismic activity and provide warnings with similar effectiveness as traditional ground seismic networks, which are not widespread in many earthquake prone countries.

The system has detected more than 1,000 earthquakes world wide since 2021, sometimes alerting people 15 seconds to 1 minutes before the shaking propagated towards them.

The idea emerged from a week long internal hackathon at Google in 2015.

Software engineer Marc Stogaitis laid down the ground work for a global network using sensors on cell phones , refining it over the years with other engineers.

It works through a phone's accelerometer, the same feature that twists your phone's screen when you rotate.

The sensor also detect vibrations, even those originating underground.

Earthquakes generate different types of seismic waves: Primary and Secondary waves.

The primary waves that occur first, and Secondary waves that are slower and usually more damaging.

When an earthquake starts, a phone's sensor can detect the Primary waves , which many people can't feel. When numerous phone simultaneously detect these vibrations, they send this signal and their location to Google's earthquake detection server.

An algorithm assess whether it is an earthquake, analysing features such as speed.

It also estimates the intensity, which helps the system decide whom to alert before the more noticeable shaking occurs.

The signals from the phone , roughly the speed of light, are traveling much faster than the speed of earthquake.

The first promising data came in 2018, when the android system detected a 7.1 magnitude earthquake in Anchorage. The system began operations in 2021 and is now available in 98 countries.

Earthquake early warning system is on by default on android - which make up to 70% of smartphones around the world - as long as location services are enabled.

The phone emits a loud, high pitched ring.

People typically receive upto 15 seconds of warning for earthquakes estimated with strongest shaking, of a magnitude of 7 or higher.

The system gave up to a minute warning for moderate shaking, of at least magnitude 5.

The alert link to a safety page with tips on what to do after an earthquake, as well as more information about the quake provided by google search.

Android users farther from the epicenter will probably receive a BeAware alert, which appears like a typical android notification and does not break through the do not disturb settings.

The TakeAction alerts break through any do not disturb settings, take over the entire screen and provide instructions like Drop, Cover and Hold on or Protect yourself.

The biggest challenge to the algorithm is estimating the magnitude, especially for stronger earthquakes.