Smartphones could become crowdsourced earthquake detectors
Scientists have found that just a few seconds of warning before an earthquake hits can make a big difference. People have time to get to a safer location, surgeries can be stopped and other protections can be implemented. While early warning systems exist, many areas prone to earthquakes don't have them because the technology is still very expensive.
A group of researchers that has been working on the West Coast’s $145 million ShakeAlert earthquake early warning system, which uses both GPS and seismometers, has come up with a solution that uses technology many of us already have in our pocket to deliver early earthquake warnings to areas that can't afford expensive systems.
Sharp jolts occurring at the fault before the more dangerous surface waves of an earthquake are what set off early warning systems. The study found that the GPS technology embedded in our phones is sensitive enough to detect vertical or horizontal movement as small as one centimeter. An app could be downloaded on users' phones in earthquake prone areas. If the apps detected a similar movement on several phones in an area indicating the first jolt of an earthquake, an alert could be sent to everyone's phones to get to a safe area.
The authors wrote in the journal Science Advances:
Commercial demand for personal mobile navigation has led to a proliferation of devices that use the same, albeit lower-quality, GNSS and Inertial Navigation Systems (INS) sensors used for EEW [earthquake early warning]. Smartphones alone currently number 1 billion worldwide and will increase to ~5.9 billion by 2019. The ubiquity of consumer devices raises the possibility that operational EEW could be achieved via crowdsourcing. For a global population exposed to ever-increasing earthquake risk, the significantly reduced costs associated with crowdsourcing could facilitate widespread EEW implementation and substantially reduce the impact of future earthquakes.
The authors tested the ability of Google Nexus 5 smartphones to detect an earthquake using simulations of a magnitude 7 quake on California's Hayward fault and a historical simulation of a magnitude 9 quake that hit Japan and found that the phones can successfully detect the initial jolts of magnitude 7 earthquakes and higher.
They found the phones could actually detect the location of the seismic event based on the amount of surface movement. If enough people in earthquake-prone areas used the app -- like a few hundred -- then residents would have a built-in early warning system.
“Probably the biggest impact would be in parts of the world that don’t have networks and can’t afford to build them,” said lead study author Sarah Minson, a geophysicist at the U.S. Geological Survey in Menlo Park, Calif. “We have high hopes that this could make a huge impact, because the vast majority of the world has no form of early warning or even rapid response to an earthquake. What people do increasingly have are these devices.”
The one major thing standing in the way of this becoming reality is that researchers would need access to phones' raw GPS data, which is blocked on smartphones. The software on phones that helps pinpoint user's exact locations, also masks earthquake signals. In order to create an early warning system, both software and firmware on smartphones would have to be updated to allow it.
The researchers are planning a trial of this technology in Chile. They will be hacking 250 smartphones to provide the raw data that they need.