Thanks to smartphones, earthquake early warning systems could one day come to parts of the world that lack fancy expensive sensor networks. Researchers at University of California, Berkeley, released MyShake on Friday, an Android app that hopes to become the future of earthquake detection. No mere makeshift seismograph, the app informs users about recent and historic quakes around the world and offers tips for mitigating damage before, during, and after a shake.
Countries without sophisticated seismic detection — think Haiti or Nepal — might be about to crowdsource their ability to find earthquakes. When a quake is approaching, that could give seconds or even minutes of warning, time enough to find cover and protect infrastructure.
“The more you have smartphones near the epicenter, the quicker we can detect the earthquake and the faster we can send out the warning,” lead author and seismology Ph.D. student Qingkai Kong tells Inverse. The study was published Friday in Science Advances.
The app constantly monitors your phone’s accelerometer to isolate earthquake movement from a phone’s normal jostling. In tests, the Berkeley algorithm correctly picked out non-earthquake noise 93 percent of the time. When the program thinks it has felt an earthquake, it alerts a central data center. By corroborating this information with other phones, the computer can determine whether or not a quake occurred — and if it did, the system will estimate the location of the epicenter, the quake’s duration, and the intensity.
If the phone’s accelerometer lacks a clear and present danger of inaccuracy, it can always find safety in numbers. The best current seismic networks have sensors no closer than six miles. “Even at some places where there is no seismic network, there are still a lot of smart phones,” Kong says. If MyShake gets serious traction, it could make those numbers look ridiculous.
Still, researchers found that the earthquake would have to be pretty strong to be detected — they can pick up magnitude 5.0 quakes at a distance within six miles. (For comparison, an earthquake of just under that size gave my house a good shake a couple months ago at a distance of about 25 miles. It felt significant to me, but my phone would have slept through it.)
Seismologists can give early earthquakes warnings when sensors detect and process an event faster than destructive waves move out from the epicenter. Because these pulses travel at about 1.5 to 2.5 miles per second, a city 100 miles from the epicenter could, optimally, get almost a minute of warning. The researchers calculate that Kathmandu could have had about a 20-second warning before feeling the earthquake that killed more than 8,000 people and devastated the region a year ago. That could have saved hundreds of lives.
For now, the MyShake will not provide warnings. But the data it generates will improve the detection system and its algorithms. The more people who download the app, the more accurate it will become. The system needs about 300 smartphones in a 70-mile square area to function reasonably well, Kong says. For now, the app is available for only Android at the Google Play store. But if it proves popular and useful, it could be later extended to other platforms.