Smartphones and other personal electronic devices could be used to detect earthquakes and alert people in poorer countries about the danger, researchers say.

Such early warning systems could be created using the devices' global positioning system (GPS) receivers, which can detect ground movement caused by a large earthquake.

By using crowd-sourced observations from participating users' devices, earthquakes could be detected and analyzed, and earthquake warnings could be sent back to users, according to the study.

While not as accurate as scientific-grade equipment, this approach could be used in countries unable to afford much more expensive earthquake early warning systems, the researchers explained.

"Crowd-sourced alerting means that the community will benefit by data generated from the community," study lead author Sarah Minson, a geophysicist at the U.S. Geological Survey, said in an agency news release.

Only a few earthquake-prone regions in the world have earthquake early warning systems, the study authors said in the news release.

"Most of the world does not receive earthquake warnings mainly due to the cost of building the necessary scientific monitoring networks," project leader and USGS geophysicist Benjamin Brooks said.

The researchers used data from a 2011 earthquake in Japan to create a simulation to test the feasibility of the crowd-sourced earthquake early warning system. They found that it would be effective even if only a small percentage of people in an affected area contributed data from their devices.

For example, the system would work if data was gathered from fewer than 5,000 people in a large city.

However, the crowd-sourced system is only effective for earthquakes of magnitude 7 or larger, not for smaller, though possibly damaging earthquakes, the investigators found.

The findings were published April 10 in the journal Science Advances.

-- Robert Preidt