When an earthquake hits, even a few seconds advance notice can be precious. Because digital communications can outrun seismic waves, scientists at the Berkeley Seismological Laboratory have designed and released MyShake, a free Android app that crowdsources earthquake detection.
The app uses the same built-in accelerometers that tell your phone when to flip its screen orientation. They’re sensitive enough to register quakes starting at magnitude 5.0—when shaking typically begins to damage built structures. After the scientists have tested it under public use, they plan to add an early warning feature, complete with a timer counting down to impact. At that point, perhaps a year from now, MyShake should be able to sense, report and alert users to an earthquake in less than a second. That would be a crucial heads-up, especially in parts of the world with no other seismic sensor network.
The brain of the app is an algorithm that picks earthquake vibrations out of the ordinary bumps, jumps and drops that phones endure daily. In tests on a shake table, the program correctly picked the vibrations of past quakes about 93 percent of the time. Once the app sees a match, the researchers explain in a paper published February 12 in the journal Science Advances, it reports to a central server along with its location. If a majority of nearby devices send the same report, the earthquake is confirmed.
“We want to get thousands of people using the app and record a couple of earthquakes to be sure that everything is working properly,” says Richard Allen, the project lead and director of University of California, Berkeley’s seismology lab. “We see this as rolling out a very dense seismic sensor, so it’s as much about recording data as it is about sending early warnings. That data will help us better understand earthquakes, how buildings respond to earthquakes and how to improve our earthquake resilience.”
Depending on their distance from the epicenter and the strength of the quake, users would get alerts anywhere between a few tenths of a second to several minutes before shaking starts.
A few seconds is enough time for people to get to a safe place, like under a table, says Allen. During California’s 1994 Northridge and 1989 Loma Prieta earthquakes, he adds, furniture, light fixtures and other falling hazards caused more than half of all injuries. It’s also enough time for automated trains to slow or stop, for elevators to go to the nearest floor to avoid trapping riders and for sensitive data servers to protect valuable information. “Early warning can reduce the overall impact so that fewer people are affected and the region as a whole can pick itself up more quickly,” says Allen.
The Berkeley Seismological Laboratory already helps oversee a network of 400 buried seismic stations in California. They’re tied into ShakeAlert, a West Coast warning system that’s under development. When a magnitude 6.0 earthquake hit South Napa in August 2014, the system sent a five to 10 second advance notice to nearby recipients such as the Bay Area Rapid Transit railway.
“ShakeAlert warnings automatically slow down all the trains. And if there is actual shaking, accelerometers on the tracks stop them,” says Taylor Huckaby, a communications officer for the railway. “That mitigates a large disaster like a train derailing. When Berkeley approached us about it we were all aboard.”
Rather than replace buried sensors, MyShake will support and multiply the data they provide. In parts of the world with no traditional seismic network, the app has the potential to quickly and cheaply increase public safety. “Nepal is a good example,” says Allen, citing the earthquakes there in April and May of 2015 that killed nearly 10,000 people. “They have no seismic stations, but there are 6 million smartphones in the country and 600,000 in Kathmandu alone. There MyShake has a real opportunity to make a difference.”
The app would be useful in such places, says Denis McClean, spokesman for the U.N. Office for Disaster Risk Reduction, so long as people know what to do once they get an alert: “They also need to understand how to react in those circumstances in a way that is safe. That is why earthquake drills are so important,” he says.
Of course the app will only work if people install it. Allen says MyShake needs at least 300 users in a given 68-square-mile area to work well. With an eye to retaining users, the scientists worked with Silicon Valley Innovation Center, part of Deutsche Telekom, to design the app to use as little memory and battery power as possible. The researchers’ dream is to get earthquake detection built into all phone operating systems, a goal that would probably require moving both heaven and earth to achieve.