Half a million phones in California have received emergency alerts for a 6.2 earthquake thanks to a system that offers a few seconds to take cover, reports TheGuardian.
In the moments before the 6.2 magnitude earthquake on the northern California coast on December 20, about half a million phones were buzzing. An early warning system operated by the US Geological Survey sent out warnings before the ground began to shake, giving residents of the sparsely populated area the time they needed to take cover.
The quake caused significant shaking, but it caused minimal damage in Humboldt County, about 330 km northwest of San Francisco, and officials said it was an excellent test of the warning system. It was the worst earthquake since the system known as ShakeAlert was officially deployed on the west coast.
“We received several reports from people that they received an alert 10 seconds before how they felt the shaking of the earth. It's pretty damn good ”, & # 8211; said Robert de Groot, ShakeAlert Coordinator at USGS.
ShakeAlert issues alerts through a number of agencies and applications, including MyShakeApp, public wireless emergency alert systems and the Google-powered Android operating system.
Data packet is generated from information provided by USGS sensors and & # 8211; within seconds & # 8211; displayed on phones. Some apps that provide alerts are available for download, but even those who didn't have an app on their phone were notified. The victims are asked to fall, take cover and hold onto something. Having extra seconds to do this can save lives.
This event provided an opportunity for scientists and system operators to test and improve the ShakeAlert so that it becomes even more efficient when the next major earthquake hits.
“We can run as many simulations and tests as possible, but we are really going to extract the most benefit from real earthquakes, & # 8211; said de Groote. “It gives us the opportunity to use the system and learn how to better warn people.”
The earthquake struck just after noon off the coast, near the tiny town of Petrolia, home to fewer than 1,000 people. The nearest town of Eureka is about 70 km to the north.
Nearly 25,000 people felt strong or very strong tremors, according to the US Geological Survey, although residents as far away as Sacramento and the San Francisco Bay Area reported feeling them too.
Humboldt County Emergency Services did not issue evacuation orders, although some roads were closed due to rockfalls. The US Geological Survey estimated the economic loss was less than $ 10 dollars and there were no fatalities.
Photos showed smashed shop windows, broken bottles falling into store aisles, and tiles falling from the ceiling of a commercial building … The area was last hit by an earthquake of similar magnitude in 1993, when one person died, according to the US Geological Survey.
Jane Dexter, store manager for the Petrolia General Store, said the crash and jolts lasted about 20 seconds. Glass bottles fell from store shelves, shattered to the floor, but no one was hurt. “This concussion was more than anything I've felt here in a long time,” & # 8211; she said.
According to the US Geological Survey, on December 20 and 21, there were dozens of tremors ranging in magnitude from 2.6 to 4.5. Although the earthquake struck off the coast, it did not trigger a tsunami, and the National Weather Service announced there was no tsunami threat.
While the number of warnings is improving, officials stressed the importance of preparation residents and visitors in earthquake-prone areas on the west coast.
“This is one of the tools in a large toolbox, & # 8211; said De Groote. -Everyone should have an earthquake emergency kit, copies of important documents, and plenty of bottled water for each family member. ShakeAlert & # 8211; it's just a security enhancement they can use. “