The UC Berkeley Seismology Lab’s MyShake app is making seismometers out of smartphones and citizen scientists out of users. As more and more people use the app, the scientists behind MyShake hope the citizen science project will eventually create a worldwide earthquake early warning network.
MyShake has been available since 2016 and now has over 300,000 downloads in more than 80 countries. The latest release two weeks ago for iOS includes “a massive update to our user interface,” said Jennifer Strauss, external relations officer for the UC Berkeley Seismology Lab (BSL). “We’re trying to build out our usership and make sure we’re providing a quality experience for everyone.”
Like the earlier MyQuake app, MyShake shows users information related to both recent and historic earthquakes, how they could potentially impact the user’s present location, and some basic safety information for how to respond in the event of a quake. The app also allows users to post reactions to recent quakes and send their observations and experiences to the BSL. For example, users could report whether or not they felt the M4.3 earthquake that hit the East Bay on the afternoon of Tuesday, July 16, and if they observed any damage to roads or buildings.
MyShake also collects data via the phone’s accelerometer — the mechanism in a smartphone that detects motion and orientation, i.e. whether a user is holding their phone in portrait versus landscape mode when they take a photo. The app records a user’s location, measures any ambient tremors and reports the information back to BSL. An early-warning alert is an eventual goal. A collection of MyShake users positioned near a tremor’s epicenter, for example, could provide data to the lab and tens of seconds of warning to app users located at a distance. But before the lab can create anything like an earthquake alert they need to gather more earthquake data. And for that they need more users.
Of course, a lot of things can set a phone’s accelerometer buzzing. Even just texting is likely to shake up a phone’s internal mechanisms more aggressively than a Magnitude 3.0 or 4.0 quake. To address that, the MyShake app has been designed to only record and report data when the phone has been at rest for several minutes.
“The signal to noise is much better when the phone is stationary,” said Strauss. “Because of that we don’t actually turn on the earthquake monitoring until the phone has been still for a bit.”
The app is designed with what Strauss refers to as an “artificial neural network” that monitors agitation and distinguishes between “acceleration signatures that look like earthquakes and acceleration signatures that look like you sitting on a train, riding a bike, sitting at a desk, or just picking up your phone,” she said.
In other words, deliberate or incidental attempts at false data won’t muddy the system. One phone’s data can be compared to other phones nearby, and taking your phone for a joyride on a pogo stick first thing in the morning won’t register anything like a quake. “The artificial neural network on an individual phone is actually pretty good at distinguishing actions,” said Strauss. “Only if the movement looks earthquake-like does it then send that information to our end.”
Sensitivity varies by make and model, but the accelerometers in some of the newer smartphones are capable of detecting earthquakes as small as Magnitude 2.0, according to Strauss, making them far more sensitive to vibrations than their users, who might easily sleep through such events.
Strauss emphasizes that the MyShake app does not track data when inactive, and neither records nor reports any data that is not connected to its function of monitoring earthquakes. “We don’t track phones as they go through life,” said Strauss.
With one exception, however. Every few hours the BSL sends out a ‘heartbeat’ or pulse to check the number of active phones within the system. Any smartphone with the MyShake app currently active then pulses back in response, giving the BSL a headcount of how many accelerometers are in the network and where they are presently located “within a fuzzy area,” said Strauss. Which is to say, city specific. MyShake can tell if a user is in Berkeley, but not which neighborhood. “And we don’t store that information,” said Strauss.
“We need to know what percentage of phones in an area are actually ready to monitor.” It’s more significant if an area has only two phones and both record tremors, than if an area has a hundred phones, and only two record.
MyShake still can’t alert users in advance of an oncoming quake. For now, BSL scientists are focused on providing a quality data-driven app to keep users informed. One use is social. “If you’ve experienced an earthquake, you can go onto the app and report your shaking, road or building damage, and see that other people in your area are having the same experience,” Strauss said.
In addition, people worried about their loved ones who live in earthquake-prone regions can get a notification on their phone without having to wait for the news reports to come in,” Stauss said. “People have reported they have great peace of mind from that.”
