Smartphones could help warn of earthquakes, scientists say

SAN FRANCISCO – Add this to your smartphone's many functions: In the near future it could help save lives by warning that a powerful, distant earthquake is about to shake the ground.

Earthquake scientists are proposing that crowdsourcing hundreds or even thousands of volunteers with their highly sensitive mobile phones could create a seismic early warning system to alert users of oncoming seismic shocks.

Seismologists in Menlo Park, Calif., and at the University of California at Berkeley are testing the phones and foresee them as particularly useful in developing regions, like Southeast Asia and parts of Africa, that are prone to large and often devastating earthquakes but where more sophisticated warning systems don't exist.

A study led by scientists at the U.S. Geological Survey found that networks of today's smartphones could issue alerts to the onset of ground shaking from earthquakes of magnitude 7 or larger. Such a network, however, would be ineffective — at least for now — for smaller quakes that can often be just as damaging as more powerful ones when they hit in crowded cities.

Benjamin A. Brooks, who led the study with USGS colleague Sarah E. Minson, said Thursday the team has received a $250,000 grant from the U.S. Agency for International Development to run an early study involving 250 smartphone detectors in Chile, where quakes of magnitude 7 or larger hit every year or two.

No early warning system exists for quakes in coastal Chile, but the country is now developing a tsunami warning system based on smartphone networks because many large quakes have triggered the often deadly coastal events.

"We hope that in a year or so we'll know how effective the phones can be for earthquake early warning," Brooks said.

It is unclear just how big a crowdsourced network must be to work as an accurate tool warning populations that a major ground-shaking event is coming, Brooks said.

In a simulated test of a magnitude-7 quake on the Hayward fault, the researchers reported that at least 100 smartphones could have detected the temblor, and that 5,000 phones would have detected it within five seconds. That's "a sufficient amount of time to issue a warning to major population centers like San Francisco and San Jose," Brooks said.