SACRAMENTO, Calif. >> Android phones will be used to sense earthquakes around the world and may one day be able to provide global warnings, with the first mass alert system unveiled today in California, Google announced.

Google, which helped develop Android, worked with California and the U.S. Geological Survey to build the quake alerts into all phones that run the commonplace mobile operating system. Android users who have enabled location services and are near a quake of magnitude 4.5 or greater will receive a full-screen earthquake warning telling them to drop to the floor and seek cover.

The screen also will provide estimates of the quake’s magnitude and distance from the user.

The alert is based on the projected shaking at a particular location and a certain level of intensity. Depending on their distance from a quake, people could get several seconds or perhaps a minute of warning.

The warnings are powered by California’s ShakeAlert system, which uses signals from more than 700 seismometers installed around the state that can sense seismic waves.

However, users won’t need to download the state’s MyShake app in order to receive the alerts. That application, developed by the University of California, Berkeley and launched last year, has been downloaded by only about 1 million of California’s 40 million residents. By contrast, many millions of people own Android phones.

“This announcement means that California’s world-class earthquake early warning system will be a standard function on every Android phone — giving millions precious seconds to drop, cover and hold on when the big one hits,” Gov. Gavin Newsom said in a statement.

IPhone users won’t receive the alerts through Apple’s operating system, but they can download the MyShake app.

Also today, Google announced that Android phones will begin detecting earthquakes from around the world through their motion-sensing accelerometers.

“Your Android phone can be a mini-seismometer, joining millions of other Android phones out there to form the world’s largest earthquake detection network,” according to a Google blog post.

More than 2 billion devices run the Android operating system.

Hundreds of millions of people live in earthquake-prone areas. But many countries lack the resources to build detection and alert systems, Google said.

The information will be used at first to provide fast and accurate information on Google Search. But Google said it could begin sending out earthquake alerts next year.