Smartphones to power earthquake early warning network
Mon 13 Apr 2015
Researchers at Caltech and the United States Geological Survey (USGS) are developing an early warning system to help detect signs of earthquakes using collective data generated from thousands of local smartphones.
The team hopes that by creating a network of smartphones, a cheap yet reliable system can be created to help save lives and protect infrastructure in earthquake zones. Currently, early warning mechanisms used in earthquake-prone regions are able to give minutes of notice before an earthquake hits, with land tremors travelling at a slower pace than modern day telecommunications, but these are expenisve to manage and operate.
Sarah Minson, USGS geophysicist and lead researcher on the report, which was published in the new journal Science Advances on April 10th, decided to look into how smartphones could be used as seismic sensors, albeit less sensitive than traditional monitoring equipment.
The group’s findings suggest that a smartphone’s GPS receiver could work to pick up on ground movements caused by earthquakes of magnitude 7 and larger. The signals would be passed across the crowd-sourced alert network and an algorithm would analyse the patterns to track where the earthquake began and how long it will take to reach an individual smartphone user.
“Thirty years ago it took months to assemble a crude picture of the deformations from an earthquake. This new technology promises to provide a near-instantaneous picture with much greater resolution,” said Thomas Heaton, co-author of the study and Caltech engineering seismology professor.
The researchers tested the earthquake early warning (EEW) system on a simulated magnitude 7 earthquake and real life data from the magnitude 9 Tohoku-oki earthquake which devastated Japan in 2011. The EEW trial was found to be a success using as little as 5,000 smartphones connected in a large urban area, to send warning signals to cities further away.
Although the current system can only detect magnitudes of 7 and above, the paper explains that further research involving microelectromechanical systems may result in better detection of earthquakes as low as magnitude 5.
“The U.S. earthquake early warning system is being built on our high-quality scientific earthquake networks, but crowd-sourced approaches can augment our system and have real potential to make warnings possible in places that don’t have high-quality networks,” said Douglas Given, coordinator of the Shake Alert Earthquake Early Warning System at USGS.
“Crowd-sourced data are less precise, but for larger earthquakes that cause large shifts in the ground surface, they contain enough information to detect that an earthquake has occurred, information necessary for early warning,” added study co-author Susan Owen.