The Perfect Earthquake Warning System Is Already in Your Pocket

​Before California ran​ out of water, its most fearsome natural disaster was earthquakes. Though it has been eclipsed in attention for the moment, the risk hasn't gone away. According to t​he United States Geological Survey, earthquakes "pose a significant risk to 75 million Americans in 39 states," and thr​ee-fourths of Californians. And that's just America! There's a whole Pacific Rim out there.

To increase that warning time, and supplement the monitoring job done by the USGS and its Shak​eAlert system, we're all already carrying another potential monitor in our pockets: smartphones. A USGS study just p​ublished in the journal Science Advances found that smartphones could form an effective earthquake early warning system for places that aren't being closely watched by scientists. In fact, they're ready to do it right now, but for one small change to the software.

"The one and only problem is that through the API in your phone you can't get the GPS data on your phone," Sarah Minson told me over the phone.

Minson is a geophysicist for USGS and lead author of the study. She laid out her vision for how a smartphone-based system would look: People would download an app that collected and anonymized the data. In order to minimize the battery drain, it could be customized to only run in the background when the phone is plugged in, or not being used or whatever. And when an earthquake hits, you have coverage everywhere, and thus more warning time that the shaking is coming.

"It would be a crowdsourced autonomous system that takes advantage not just of millions of devices that are sensors, but millions of devices that are tiny computers," Minson explained. "Each one could be analyzing its own data, and determining whether it thinks an earthquake is happening and if enough phones together thought they were having an earthquake, it would trigger a warning."

Since we still can't predict when earthquakes will hit, the best thing we can do is warn people when they have hit. The damaging waves of an earthquake travel at two miles a second, so depending on how far people are from the earthquake, warnings can give a narrow window of time where they can get under a table, or pull over their cars, or stop performing surgery, or whatever. Early warnings, even for less damaging earthquakes, make the psychological experience of everything shaking less terrifying.

What's cool is that your phone is already equipped to pick up, at least, fairly large, magnitude seven earthquakes or above.

"All of the hardware we were looking at was just the phones themselves," Minson said. "The hardware on your phone is amazing. It can do incredible things. In fact the only thing that's stopping us from taking advantage of this tomorrow is the fact that unfortunately those data typically aren't available to users of the phone."

The problem is that, right now, earthquake-relevant data gets filtered out by your phone. In Minson's word's, "your phone is very clever."

"The GPS in your phone is shockingly accurate, but your phone is very clever: when you hit geolocate on your phone it doesn't give you your GPS position. It also checks with your accelerometer to see if you're walking or if you're driving and using that information. It tries to give you the best position by stamping out extraneous noise," she said. "Unfortunately this post processing completely masks any earthquake signal. I guess to the processing, earthquakes look like noise. The phones are amazing, and if there was only a way to access GPS data, they could do incredible things. The hardware itself is great. It requires an OS change."

Of course, many of the people responsible for how your phone works live in California, and therefore have a not-exactly-impersonal stake in earthquake monitoring, so it seems conceivable that they'd be interested in changing this little quirk.

But the real value of a smartphone net may be well beyond the world of Silicon Valley programmers, in places that don't have a geological survey watching for earthquakes.

"Smartphones are becoming fairly ubiquitous, even in fairly underdeveloped countries," Minson said, "whereas most places in the world can't afford the investment of installing a dense network of seismometers and GPS that would create an early warning system."

With that in mind, a one-year pilot version of this project was just funded last week, and will be tested in Chile. And with some luck and some software updates, we'll see it functioning back home.