What would you do with an early warning about an earthquake? Would it help you or others and possibly safe lives? Officials in California are planning the first major rollout of an earthquake early warning system next year, providing access to some schools, fire stations and more private companies. The ambitious plan highlights the progress scientists have made in building out the system, which can give as much as a minute of warning before a major earthquake is felt in metropolitan areas.
Until now, only academics, select government agencies and a few private firms have received the alerts. But officials said they are building a new, robust central processing system and now have enough ground sensors in the Los Angeles and San Francisco areas to widen access. They stressed the system is far from perfected but said expanded access will help determine how it works and identify problems.
The warnings would allow fire stations to get garage doors open before a quake can jam them shut, instruct students to duck and cover, and, eventually, automatically shut off sensitive equipment at private companies and tell surgeons to halt surgery. When the data is more reliable, even amusement parks could have time to shut down rides.
The prospect of expanding the system — which is dependent on federal funding coming through — has brought excitement for both emergency officials and some businesses. Even a few seconds’ notice to duck under a sturdy desk could be a matter of surviving a building’s collapse, fire officials said.
The prototype developed by the U.S. Geological Survey and universities including Caltech and UC Berkeley has scored a series of successes, generating alerts in Pasadena before shaking arrived from the 4.4 Encino, 5.1 La Habra and 4.2 Westwood earthquakes earlier this year. San Francisco got eight seconds of warning before strong shaking arrived from the 6.0 Napa earthquake in August.
The early warning system works on a simple principle: The shaking from an earthquake travels at about the speed of sound — slower than the speed of light. That means it would take more than a minute for, say, a 7.8 earthquake that starts at the Salton Sea to shake up Los Angeles 150 miles away.
Seismic sensors stationed at the Salton Sea would detect the first shaking waves in as little as 5 seconds, and blast a warning throughout Southern California. In this scenario, Palm Springs would have 20 seconds of warning; San Bernardino, 45 seconds; and the Los Angeles area, more than a minute.
What could you do with 10 – 60 seconds of warning?