Android is becoming a worldwide network for earthquake detection

Google is creating a worldwide, Android phone-powered earthquake alarm system. The first part of that system runs out today. When you log in, the accelerometer in your Android phone will become one data point for an algorithm designed to detect earthquakes. Eventually, that system will automatically send alerts to people who may be affected.

It’s a feature made possible by Google’s strengths: the sheer number of Android phones around the world and clever use of algorithms on big data. As with its collaboration with Apple on exposure tracking and other Android features such as auto-crash detection and standards location services, it shows that there are untapped ways in which smartphones can be used for something more important than doomscrolling.

Google runs the system in small stages. First, Google is participating in the U.S. Geological Survey and the California Office of Emergency Services to send the earthquake warnings of the agencies to Android users in that state. These alarms are generated by the existing ShakeAlert system, which uses data generated by traditional seismometers.

“It would be great if there were just seismometer-based systems everywhere that could detect earthquakes,” says Marc Stogaitis, principal Android software engineer at Google. But, he continues, “that’s not really practical and it’s not likely to have worldwide coverage, because seismometers are extremely expensive. They have to be constantly maintained, you need a lot of them in an area to really get a good one. earthquake early warning system. “

That the second and third stages of Google’s plan will instead be powered by Android phones. However, the company is going pretty cautiously. In the second stage, Google will show localized results in Google search for earthquakes based on the data it has detected from Android phones. The idea there is that if you feel an earthquake, you go to Google to see if that’s what you felt or not.

Image: Google

Finally, once it has more confidence in the accuracy of the system, Google will actively begin sending earthquake warnings to people living in areas where there are no seismometer-based warning systems.

Stogaitis says that the information collected as part of this program is “de-identified” by users and that Google only needs “rough” location information to work. Both the earthquake warnings and the detection system are also enabled. “What we really need here are just those little mini-seismometers that are out there,” Stogaitis says. “We do not need to know anything about the person sending it, because that does not matter.”

An Android phone can become a “mini-seismometer” because it has an accelerometer – the thing that detects whether you have rotated it or not. Android’s system uses the data from that sensor to see if the phone is shaking. It is only on when an Android phone is plugged in and not in use, to conserve battery life.

‘We knew it [Android phones are] sensitive enough to detect earthquake waves. When an earthquake wave continues, they are able to detect it and normally see both major types of waves, the P-wave and the S-wave, ”says Stogaitis. “Every phone is capable of detecting something like an earthquake, but then you need an aggregate phone to know that it’s certain that an earthquake is happening.”

The P wave (primary wave) is the first and fastest wave sent from the epicenter of an earthquake. The S-wave (secondary wave) is slower, but can be much larger. Google’s system can detect both. “Often people will not even feel the P-wave because it is just smaller, while the S-wave tends to cause much more damage,” says Stogaitis. “The P-wave can be something that tells you to prepare for the S-wave.”

That data is processed in the classic Google way: using algorithms on the composite data of thousands of phones to determine if an earthquake occurs. Where traditional seismometers are expensive and precise, Android phones are cheap and very expensive. Google can use Bayesian filters and other algorithms to turn those numbers into earthquake data just enough to send warning messages.

Google says its system is capable of locating the epicenter and determining the magnitude of an earthquake. Even the basic physics of those waves means that there are limits to what is possible, he explains:

The biggest important thing is that the phones that are closest to the earthquake can help users to know away from the earthquake about it. One of the limitations of the system is that we can not warn all users before an earthquake reaches them. The users closest to the epicenter of the earthquake are unlikely to receive a warning on time, as we do not predict earthquakes in advance.

This speed also means that Google’s Android-based alert system does not have a human in the loop, as these alerts will range from “a few seconds” near the epicenter to 30 or 45 seconds on the outside.

“We have a lot of seismologists on the team who are literally just embedded with us,” Stogaitis says. That includes Richard Allen, ‘who warned of early earthquakes for most of his career [systems] and who contributed a lot to the design of ShakeAlert system, and who in the past also built a telephone-based earthquake detection system. “

Allen’s MyShake app is an earlier example of a system like this – but the difference now is that Google can build that detection directly into Android and can do so on Google’s scale. (Unlike Google’s system, MyShake works on iPhones.)

Google’s intention is to have different levels of warnings for different earthquakes. It has consulted with seismologists not only about the design of the nuclear system, but also about how the warnings should appear. The goal is to “convey information in the shortest possible time so that users can understand that they need to respond very quickly to an earthquake without reading an enormous wall of text,” says Stogaitis.

Image: Google

In the long run, Google hopes to create an API based on its earthquake detection system. It does not intend to use this system on iPhones, but if the API comes out, Apple would be free to use it. More interesting it is, however other systems would benefit from an earthquake detection API.

For example, if someone can build something that automatically stops an elevator on the next floor and opens the door so people can get out before the wave comes. And you can turn off gas valves automatically, you can have something that stops medical procedures, or open the door to fire stations in advance. That’s a common problem with earthquakes where fires are quite a deal and firefighters simply can not get out. That, you can build something that does that. Aircraft can stop landing if they do so, dropping their landing. Trains can slow down. There is a whole ecosystem that could be enabled by using these Android tracking and having it to just publish server side so others can plug in it.

The stakes for such a system would be incredibly high – and the responsibility for maintaining that system would be equally high. That API is a long way off. Google’s plan is to minimize false positions and tune the system at this time. Google also had to make a concerted effort to ensure that notifications do not overwhelm its networks. Sending a ping to any Android phone at the same time has the potential to stop those airwaves.

Google will roll out this system through Google Mobile Services so that it does not require a complete operating system update. This means that both the detection system and the alerts should work on the vast majority of Android phones in use today. (It also means that these services will not be coming to China anytime soon, because Android phones in that country do not use Google services.)

Google immediately starts issuing earthquake alarms in California, using the existing seismometer network. Earthquake data will also soon appear again in Google searches. As for the warnings and cautions based on the data collected from Android phones, that will take a little more time. Google says that if a region has an existing earthquake detection and warning system, then it is preferable to use it instead of the phone-based system.

“Basically, there are hundreds of millions of people around the world who live near earthquake faults,” says Stogaitis, “and that’s something we think we can help with.”