The tool uses ground motion sensors to detect earthquakes before humans can feel them and send automated notifications.
The California Earthquake Early Warning System will combine a new smartphone app with traditional alert and warning delivery methods such as Wireless Emergency Alerts (WEA).
The tool, now being tested state-wide, uses ground motion sensors to detect earthquakes before humans can feel them and automatically notify Californians. The app can provide seconds of warning, alerting people to ‘drop, cover and hold on’.
Earthquake-prone countries like Mexico and Japan have long had earthquake early warning systems, with alerts typically delivered through phones or public address systems. California will be the first state in the US to offer such a system, following legislation requiring this.
California will be the first state in the US to offer an earthquake early warning system.
October 17 marked the 30th anniversary of the Loma Prieta earthquake on California’s Central Coast which resulted in 63 deaths and 3,757 injuries.
Over 143 million people are exposed to potentially damaging earth-shaking in the United States, with 50 million of them in California, Oregon and Washington. California has a 99.7 per cent chance of a magnitude 6.7 or larger earthquake in the next 30 years, and Oregon and Washington have a 10 per cent chance of a "devastating" magnitude 8 to 9 earthquake in the Cascadia subduction zone, experts say.
Designed by the University of California, Berkeley seismologists and engineers, the state earthquake early warning app will initially deliver alerts to people for earthquakes exceeding magnitude 4.5 in their area.
Warnings delivered through the system are based on the ShakeAlert programme, operated by the US Geological Survey (USGS). It analyses data from seismic networks, calculates preliminary magnitudes and then estimates which areas will feel shaking.
Warnings delivered through the system are based on the ShakeAlert programme.
The amount of advance notice people receive will depend on how far they are from the epicentre of the earthquake, varying from seconds to tens of seconds. However, there will be users near the epicentre who do not receive the alert before they feel shaking.
“This will often happen when a user is within a few tens of miles of the earthquake’s epicentre because of the time it takes to characterise an earthquake’s size and likely shaking levels, as well as delays resulting from the technologies our partners use to deliver the alert,” said Jeff McGuire, earthquake early warning chief scientist, USGS.
As the seismic network is expanded and the ShakeAlert system and modes for communicating the alerts are further developed and tested, the speed, reliability and public use of alerts should also increase, he said.
Gavin Newsom, Governor of California, commented: “Nothing can replace families having a plan for earthquakes and other emergencies.
"We know the Big One might be around the corner. I encourage every Californian to download this app and ensure your family is earthquake-ready.”
Mark Ghilarducci, director of the Governor’s Office of Emergency Services, added: “[The] announcement reflects our commitment at Cal OES and across the administration to use the best available science and technology for earthquake detection and warning. These early notifications greatly increase our ability to prevent injuries and even save lives.”
You might also like: