Smartphones to predict earthquakes
19 Jun 2015 by qwwqdccwwm.d qwwqdccwwm.d
Geophysicists have discovered that GPS sensors in smartphones could be used as an earthquake warning system.
By using data from hundreds of smartphones, scientists at the U.S. Geological Survey believe that sensors in smartphones and similar devices could be used to build a crowd-sourced earthquake alert system.
“Crowd-sourced alerting means that the community will benefit by data generated from the community,” said research leader Dr Sarah Minson.
In the study, published in the AAAS journal Science Advances, the team believes that combining the data from these devices can detect permanent ground movement. By using crowd-sourced data from participating users’ devices, scientists could detect and analyse earthquake probability and transmit warnings back to users.
To test the feasibility of the Earthquake Early Warning (EEW) system, the scientists simulated a hypothetical earthquake of magnitude of seven on the Richter scale, and used real data from the 2011 magnitude of nine Tohoku earthquake. The results showed that crowd-sourced EEW could be achieved with only a tiny percentage of people in a given area contributing information from their smartphones.
“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,” said research partner Dr Susan Owen of NASA's Jet Propulsion Laboratory in California.
The results also showed that the number of smartphones needed to trigger such a warning would depend on the type of the smartphone, the size of the earthquake, and the number of phones needed to minimise false alarms. The team believes that if phones from less than 5000 people in a large urbanised area responded, the earthquake could be detected and analysed fast enough to issue a warning. However, the sensors can only distribute warnings for earthquakes of magnitude of seven or larger.
To create this crowd-sourced warning system, smartphone manufacturers would have to allow consumer smartphones to access data known as C/A-code data which is a minor software fix.
The researchers believe that the consumer-quality GPS data will be less accurate than scientific-grade equipment, but it could be used as a cheaper and easier way to distribute warning in areas without scientific-grade coverage.
