In recent years we've seen a few tech developments that aim to crowdsource earthquake detection and early warning systems. It's known that only a few seconds' warning -- enough time for someone to seek cover or stop using dangerous machinery -- can have a life-saving effect.
Smartphones are the ideal crowdsourcing instrument. Millions of people have them with at all times and they already come outfitted with the necessary tools to detect and measure ground vibrations.
Researchers at University of California Berkeley developed the MyShake app that was released in February of this year to take advantage of smartphones' sensors and built-in instruments. The free Android app uses the phone's accelerometer and GPS to measure the strength of vibrations and where they're being felt.
Since its release, 220,000 people have downloaded the app and at any given time close to 10,000 of those are active and ready to detect motion -- turned on, lying on a horizontal surface and connected to WiFi. Since February, 400 earthquakes have been detected in places like Chile, Japan, China, California and, notably, the fracking fields of Oklahoma.
The app measure ground motion and then sends the information to Berkeley Seismological Laboratory for analysis. Right now, the data is collected and used to show app users where recent earthquakes have occurred, but the goal is to start issuing alerts when initial movements are felt. The researchers say that the data they've collected over the past few months has proven that phones are sensitive enough and there are enough users in earthquake prone areas to detect those first vibrations.
The app was able to detect the first seismic waves that arrive -- the P waves, which are less destructive -- which could give them enough time to issue warnings before the more dangerous S waves arrive.
"We already have the algorithm to detect the earthquakes running on our server, but we have to make sure it is accurate and stable before we can start issuing warnings, which we hope to do in the near future," said UC Berkeley developer and graduate student Qingkai Kong.
A new version of the app was just released that does issue notifications of nearby earthquakes but not early warnings. The app can detect an earthquake as small as a 2.5 magnitude where there is a good density of phones. In the trial period, the greatest number of phones to detect a quake was 103 that picked up the vibrations from the 5.2 magnitude quake that hit Borrego Springs, Ca. in June. The largest quake detected was a 7.8 magnitude one in Ecuador in April felt by two phones over a hundred miles from the epicenter.
The leader in amount of earthquakes though was Oklahoma where hundreds of quakes were set off from hydraulic fracking.