Asphalt road cracked and broken from earthquake

Earthquake alerts coming to Android phones

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Google’s Android phones have started detecting earthquakes around the world to provide data that could give billions of users precious seconds of warning of a tremor, with the feature first being rolled out in California.

Japan, Mexico and California already use land-based sensors to generate warnings, aiming to cut injuries and property damage by giving people further away from the epicentre of an earthquake seconds to protect themselves before the shaking starts. If Google’s approach for detecting and alerting proves effective, warnings would reach more people, including for the first time Indonesia and other developing countries with few traditional sensors. 

Google said it will start working with the US Geological Survey to send earthquake alerts to Android devices, starting in California. Android will send alerts to phones in California from the ShakeAlert earthquake early warning system.

“With the growing cost of natural disasters worldwide, we saw an opportunity to use Android to provide people with timely, helpful earthquake information when they search, as well as a few seconds warning to get themselves and their loved ones to safety if needed,” Google said in a blog post.

Google noted that not all quakes are in California, as evidenced by a series of tremors in Virginia and North Carolina last weekend. The company says Android phones can be turned into mini seismometers to detect when earthquakes occur and to send advanced signals to the alerting system.

“As a first step, the earthquakes that this system detects will be used to improve the speed and accuracy of earthquake information on Google Search,” Google added in the blog post. “And in the near future, we'll use this technology to send early alerts to Android users in impacted areas.”

Seismology experts consulted by Google said turning smartphones into mini-seismographs marked a major advancement, despite the inevitably of erroneous alerts from a work in progress and the reliance on a private company’s algorithms for public safety. More than 2.5 billion devices, including some tablets, run Google’s Android operating system.

“We are on a path to delivering earthquake alerts wherever there are smartphones,” said Richard Allen, director of the University of California Berkeley's seismological lab, who has been collaborating with Google on the project.

Google’s programme emerged from a week-long session four-and-a-half years ago to test whether the accelerometers in phones could detect car crashes, earthquakes and tornadoes, said principal software engineer Marc Stogaitis. Accelerometers – sensors that measure direction and force of motion – are mainly used to determine whether a user is holding a phone in landscape or portrait mode.

The company studied historical accelerometer readings during earthquakes and found they could give some users up to a minute of notice. As of late, Android phones can separate earthquakes from vibrations caused by thunder or the device dropping only when the device is charging, stationary and has user permission to share data with Google.

“They’re even sensitive enough to detect the P-wave, which is the first wave that comes out of an earthquake and is typically much less damaging than the S-wave which comes afterward,” Google said.

If the phone detects something that it thinks may be an earthquake, it sends a signal to Google’s earthquake detection server, along with the location of where the shaking occurred. The server then combines information from many phones to figure out whether an earthquake is occurring.

Google said it expects to issue its first alerts based on accelerometer readings next year. It also plans to feed alerts for free to businesses that want to automatically shut off elevators, gas lines and other systems before the shaking starts.

To test its alerting abilities, Google is drawing in California from traditional government seismograph readings to alert Android users about earthquakes, similar to notifications about kidnappings or flooding.

According to Stogaitis, people expected to experience strong shaking would hear a loud dinging and see a full-screen advisement to “drop, cover and hold on”. Those further away would get a smaller notification designed not to stir them from their sleep, while people too close to be warned will get information about post-quake safety, such as checking gas valves. Stogaitis added that such alerts will only trigger for earthquake magnitudes 4.5 or greater and that no specific app download is necessary.

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