Whoa, did you feel that earthquake? Even if you didn't, your phone did, and a new app from seismologists aims to capture those vibrations in your very own pocket seismology lab.
The University of California Berkeley's Seismological Laboratory revealed the new app, which they have dubbed MyShake, at the AAAS meeting today and simultaneously released it on Google Play. The app works by using your phone's existing sensors to pick up, record, and analyse data on earthquakes in the area. The goal is to create an impromptu worldwide, always-on network monitoring earthquakes every place you can get a phone -- and it could also eventually double as an early earthquake warning system.
MyShake has already had early success in picking up earthquake data, Qingkai Kong, a graduate student at the University of California Berkley and the designer of the algorithm for the app, told Gizmodo. "From our tests, the sensors in the smartphone can reproduce the shaking very well, and also, our algorithm can trigger on the earthquakes we tested as well," he said. "We recorded the Napa M 6.0 earthquake in 2014 on some phones that running at Berkeley, which also shows good match compare with a close by station."
But even if the phones can record the shaking data, can it really distinguish between earthquake shaking and, say, your phone dropping off a balcony, then tumbling it's way down a flight of stairs? (Yes, it's happened.) It can, says Kong. The key is training the algorithm to recognise differences in the patterns of earthquake shaking and other kinds of shaking:
"We tried to find some features that best characterise the difference behind the two different type of motions, and trained the algorithm to memorise these features," he said. "So whenever the phone records some new movements, it will compare the new motion with the features to decide whether this is an earthquake or this is from human activity."
For now, the app is just available to Android users, a decision the developers say was made (at least in part) because they represent a larger share of the global cell phone users than iOS. Eventually, though, they plan to get an iPhone app up and running too. The more phones in the area that run the app, the more likely they are to get good data. Just 300 mobile phones in a square of 1 degree longitude and 1 degree latitude (just over 100 kilometers on each side) should be enough to get a measurement.
Of course, the data is not much to compare, at least in terms of detail, with what researchers can get from a traditional seismic station -- but what it lacks in detail, it could make up for in quantity. "There are much more smartphones these days than the seismic stations," Kong said. "The large number will compensate the relatively low quality in some ways."
Top image: 1959 Hebgen Lake Earthquake / USGS; Middle image: MyShake app