Google turns Android mobiles into earthquake sensors .The first step is the integration of the ShakeAlert application in California. Googl...
Google turns Android mobiles into earthquake sensors .The first step is the integration of the ShakeAlert application in California.
Google is creating a global earthquake warning system, powered by Android phones. The first part of this system was set up yesterday. If you opt for this system, the accelerometer (sensors that measure the direction and force of movement) on your Android phone will become a data point for an algorithm designed to detect earthquakes. Eventually, this system will automatically send alerts to people who may be affected.
It's a feature made possible by Google's strengths: the staggering number of Android phones around the world and the intelligent use of algorithms on large data sets. As is its collaboration with Apple on exhibition tracking and other Android features such as car accident detection and emergency location services.
Google is deploying the system in small steps. First, Google is partnering with the United States Geological Survey and the California Office of Emergency Services to send agency earthquake alerts to Android users in that state. These alerts are generated by the existing ShakeAlert system, which uses data generated by traditional seismometers. Marc Stogaitis, senior Android software engineer at Google says:
"It would be great if there were seismometer-based systems everywhere that could detect earthquakes. But it's not really practical and it's unlikely that there will be global coverage because seismometers are extremely expensive. They have to be constantly maintained, it takes a lot of them in a region to have a really good earthquake early warning system,"
The second and third steps of Google's plan will therefore be powered by Android phones. But the company is being cautious. In the second stage, Google will display localized results in earthquake searches based on the data it detects from Android phones. The idea is that when you feel an earthquake, you're going to go to Google to see if that's what you felt or not. Finally, once it has more confidence in the accuracy of the system, Google will start actively sending earthquake alerts to people who live in areas where there is no seismometer-based alert system.
Stogaitis says that the information collected under this program is depersonalized for users and that Google only needs "coarse" location information to operate. Both the seismic alerts and the detection system are optional memberships as well.
"What we really need for this are these little mini seismometers that are there. We don't need to know anything about who's sending it because it doesn't matter," says Stogaitis.
An Android phone can become a 'mini seismometer' because it has an accelerometer. The Android system uses the data from this sensor to see if the phone is shaking. It is only activated when an Android phone is charging and not in use, to preserve battery life.
"We've found that Android phones are sensitive enough to detect seismic waves. When an earthquake wave passes by, they are able to detect them and usually see the two main types of waves, the P-wave and the S-wave. Every phone is able to detect that something like an earthquake is happening, but then you need a set of phones to make sure it's an earthquake," explains Stogaitis.
The P-wave (primary wave) is the first and fastest wave emitted from the epicentre of an earthquake. The S-wave (secondary wave) is slower, but can be much larger. Google's system is able to detect both.
"Often people won't even feel the P-wave because it's just smaller, whereas the S-wave tends to cause much more damage. P-wave can be something that tells you to be prepared for S-wave,"says Stogaitis.
This data is processed in the classic Google way: using algorithms on the aggregated data from thousands of phones to determine if an earthquake is occurring. Where traditional seismometers are expensive and accurate, Android phones are cheap and plentiful. Google can use Bayesian filters and other algorithms to transform these numbers into earthquake data accurate enough to send alerts.
Google says its system is able to locate the epicenter and determine the strength of an earthquake. Even so, the fundamental physics of these waves means that there are limits to what is possible, he explains:
"Most importantly, phones closest to the earthquake can help users farther away to know about it. One of the limitations of the system is that we can't warn all users before an earthquake reaches them. Users closest to the epicenter of the earthquake are unlikely to get a warning in time, as we do not predict earthquakes in advance.
This speed also means that Google's Android-based warning system will not have humans in the loop, as these warnings will range from "seconds" near the epicentre to 30 or 45 seconds outside.
"We have a lot of seismologists on the team who are literally just integrated with us. One of them is Richard Allen, who has spent most of his career working on earthquake early warning systems and was instrumental in the design of the ShakeAlert system, and who has also built a telephone earthquake detection system in the past," says Stogaitis.
Allen's MyShake application is an earlier example of such a system, but the difference is that Google can integrate this detection directly into Android and can do it Google-wide. Unlike Google's system, MyShake works on iPhones.
Google's intention is to have different alert levels for different earthquakes. It has consulted seismologists not only on the design of the basic system, but also on how the alerts should appear. The goal is to get the information out as quickly as possible in a short period of time so that users can understand that they have to react very quickly to an earthquake without reading a huge wall of text.
In the long term, Google hopes to create an API based on its earthquake detection system. It doesn't plan to use this system on iPhones, but if the API comes out, then Apple would be free to use it. But it is more interesting to see what other systems might benefit from an earthquake detection API.
For example, someone could build something that would automatically stop an elevator on the next floor and open the door so people could get out before the wave comes. And you can close the gas valves automatically, you can have something that stops medical procedures, or open the fire station door in advance. This is a common problem in earthquakes where the fires are very large and the firefighters often can't get out. So you can build something that does that. Airplanes can stop landing while they're doing that, interrupt their landing. The landing gear can be slowed down. There's a whole ecosystem that could be activated by using this Android-based detection and publishing it on the server side for others to connect to.
The stakes of such a system would be incredibly high - and the responsibility for maintaining it would be just as high. So this API is still far from being a reality. Google's plan is to minimize false positives and fix the system now. Google has also had to work hard to ensure that its notifications would not overwhelm cellular networks. Pinging all Android phones at the same time risks clogging up those airwaves.
Google will deploy this system via Google's mobile services, which will avoid the need for a full operating system update. This means that the detection system and alerts should work on the vast majority of Android phones in use today.
Google is starting to provide immediate earthquake alerts in California, using the existing seismometer network. Earthquake data will also begin to appear in Google searches in the near future. Alerts and warnings based on aggregated data from Android phones will take a little longer. Google says that if a region has a seismic detection and warning system in place, it is preferable to use that system rather than one based on phones.
"Basically, there are hundreds of millions of people around the world living near seismic fault zones, and that's something we think we can help," says Stogaitis.