Smartphones Can Be Your Early Warning System For Earthquakes

Having a large network of distributed seismometers is the best method of potentially lifesaving early earthquake detection; however, it is prohibitively expensive to install and maintain such a network in many countries particularly those in the developing world. Now researchers have shown that the global position system (GPS) feature of smartphones – a sensor network we’re all carrying around anyway – can also act as an early earthquake warning system.

The future of earthquake detection: the GPS feature of standard smartphones can help scientists rapidly determine the location and magnitude of earthquakes. Image by LG??.The future of earthquake detection: the GPS feature of standard smartphones can help scientists rapidly determine the location and magnitude of earthquakes. Image by LG??.

Earthquake early warning (EEW) systems work by using a sensor network to pinpoint the location of the earthquake initiation and estimating its magnitude. This permits those outside the epicenter to be notified a precious few moments in advance allowing, for example, the emergency shut down of gas pipelines or nuclear power plants and saving lives.

In order for a sensor to be useful in earthquake detection, its movement must be able to be accurately measured. Smartphone GPS systems do provide relatively crude measurements when compared with scientific grade seismometers; however, they have the advantage of offering a huge number of data points thanks to their ubiquity. Over 1 billion smartphones are currently in use worldwide with this number predicted to increase to close to 6 billion in the next 5 years. The researchers found a method to pass the huge amount of smartphone movement data through a computational filter programmed to distinguish tremor-type earth surface displacements from other types of everyday movement. The filter also mandates that a minimum number of phones must be reporting tremor motions in order to avoid false positives.

The scientists tested their system in two scenarios: a simulated magnitude 7 earthquake striking a fault in California, and the real-life magnitude 9 quake that struck Japan in 2011. In the case of the former, even with only 0.2% of the smartphone population reporting, the quake was detected in 5 seconds – fast enough to issue advance warning to nearby population centers – and the epicenter was localized to within 5 kms. In the case of the Japanese quake, detection would have taken 77 s and after 100 s the epicenter would have been located to the same accuracy as with typical scientific instruments. While detection is much slower in this case, this EEW system still would have allowed a warning to be issued before Tokyo was affected and would have provided minutes of warning before the arrival of the tsunami.


Devestation wrought by the 2011 Japanese earthquake: smartphone-based detection could have provided minutes of warning before the tsunami struck. U.S. Marine Corps photo by Lance Cpl. Garry WelchDevestation wrought by the 2011 Japanese earthquake: smartphone-based detection could have provided minutes of warning before the tsunami struck. U.S. Marine Corps photo by Lance Cpl. Garry Welch

What is particularly amazing about this result is that it was achieved using technology that is already in existence. No extra costs beyond those of data monitoring were required. Given that smartphone GPS systems are destined to become increasingly advanced in the coming years, and that smartphones are becoming more and more prevalent, this means of earthquake monitoring is a remarkably useful innovation that is only going to become more relevant.