L.A. unveils earthquake early warning app

First published on the DailyMail.com on January 2nd. Los Angeles has released an earthquake warning app that could give LA County residents precious seconds to drop, cover and hold on in the event of a quake.

The city announced on Wednesday that ShakeAlertLA is available for download on Android and Apple phones.

Based on a warning system developed by the U.S. Geological Survey, the app will alert users when there's a quake of magnitude 5.0 or greater in the state.

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Los Angeles has released an earthquake warning app that could give LA County residents precious seconds to drop, cover and hold on in the event of a quake

Depending on where the quake hits, the app says the warning could arrive before, during or after the quake.

It urges people who see the alert or feel the shaking to take precautions to avoid injury.

‘I actually think that we can say today that ShakeAlert is the most sophisticated earthquake early warning system in the world,’ said Richard Allen, director of UC Berkeley’s Seismological Laboratory following a test earlier this year.

‘The challenge is getting that alert out to every single individual across the state of California or across the Pacific Northwest.

‘The reason is that the technology for delivering alerts to all 8 million residents of the Bay Area within a second does not exist today.' 

Both Mexico and Japan already use public apps that can provide real-tie warnings to the public via text, the researcher notes.

ShakeAlert comes five years in the making, through the collaboration of the USGC, UC Berkeley, California Institute of Technology, and the University of Oregon.

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Depending on where the quake hits, the app says the warning could arrive before, during or after the quake. It urges people who see the alert or feel the shaking to take precautions to avoid injury

It could provide up to tens of seconds notice ahead of ground tremors in the area, giving people time to take cover and hold on.

The app is now in its second version as it’s being rolled out to the public, using an updated algorithm to pull data from seismic networks across the state.

With the new algorithm, the team is hoping to cut down on false alarms.

HOW ARE EARTHQUAKES MEASURED?

Earthquakes are detected by tracking the size, or magnitude, and intensity of the shock waves they produce, known as seismic waves.

The magnitude of an earthquake differs from its intensity.

The magnitude of an earthquake refers to the measurement of energy released where the earthquake originated.

Magnitude is calculated based on measurements on seismographs.

The intensity of an earthquake refers to how strong the shaking that is produced by the sensation is.

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A 5.3 magnitude earthquake hit the Channel Islands off the coast of southern California on Thursday at 10.30am

According to the United States Geological Survey, 'intensity is determined from the effects on people, human structures and the natural environment'.

Earthquakes originate below the surface of the earth in a region called the hypocenter. 

During an earthquake, one part of a seismograph remains stationary and one part moves with the earth's surface.

The earthquake is then measured by the difference in the positions of the still and moving parts of the seismograph. 

The network-based approach on which it relies isn’t as speedy as a single, or ‘on-site’ approach, but it’s far more accurate.

‘Using a network of seismic sensors also has the advantage that the system is constantly exercised and tested as it detects daily small earthquakes,’ the ShakeAlert team explains on the website.

‘For this reason the system maintains a high level or readiness.

The network approach is also the only kind capable of ‘characterizing large, complex earthquakes as they evolve.’

 

https://www.dailymail.co.uk/sciencetech/article-6550265/Los-Angeles-unveils-earthquake-warning-app.html