The reason those residents didn’t get an alert was because the quake didn’t reach the threshold on the Modified Mercalli Intensity Scale. The quake and alert controversy prompted questions to San Francisco city officials about whether San Franciscans would receive an alert before or during a quake in the Bay Area.
A spokesman from the city’s Department of Emergency Management, Francis Zamora, said to the San Francisco Chronicle at the time that it may not be practical to push out an alert in the event of an earthquake. “It’s possible you could get an alert after the earthquake,” he said.
San Francisco’s executive director of Emergency Management, Mary Ellen Carroll, yesterday clarified in an email to Emergency Management that San Francisco is prepared to send out alerts to residents, businesses and visitors through multiple platforms in the event of a disaster. “If an [earthquake alert] app is developed and verified that can send timely earthquake alerts in the Bay Area, we would be very interested in determining its potential use in San Francisco,” Carroll wrote.
The state of California has been developing the ShakeAlert earthquake early warning system in collaboration with the U.S. Geological Survey since 2006. The state recently committed $42 million through the California Department of Emergency Services to develop the California Earthquake Early Warning System.
“While San Francisco is cautiously optimistic that the earthquake early warning application may be worthwhile in the near future, we are evaluating rollout of the Los Angeles earthquake early warning application, ShakeAlertLA, and lessons learned from its most recent, significant earthquake,” Carroll wrote.
She said that public information is important following an earthquake and that San Francisco has thresholds to issue emergency alerts following any magnitude 4.0 or higher event in the San Francisco Bay Area. She said the messages are pre-scripted and vary in content depending on the damage caused by the quake. For example, in a minor quake, the message would emphasize not calling 911 just to report the quake. A more serious quake would trigger a message that would focus on life safety.
One of the concerns San Francisco has is whether a potential ShakeAlert app would send a timely alert given San Francisco’s proximity to the San Andreas and Hayward faults.
“We have already implemented the earthquake early warning system in public safety facilities, including our 911 Dispatch Center, so dispatchers would receive a warning to drop, cover and hold on,” Carroll wrote. “We also are evaluating other ways to implement earthquake early warning such as triggering auto-opening of fire station garage doors, and possibly integrating earthquake warning technology within schools.”
Carroll said the San Francisco Department of Emergency Management was one of the “early evaluators” of the ShakeAlert system and conducted a demonstration project to look at the possibilities of pushing out mobile alerts. She said they were encouraged, but “Also understand that there are factors that need to be worked out to ensure earthquake alerts and warnings are timely.”
With such proximity to the San Andreas and Hayward faults, if the epicenter of a quake were near San Francisco, the early warning sensors could be triggered at the same time or even after the shaking is felt. “In these instances, it may not be practical to push out an alert notification.”
For now, San Francisco will use numerous alert, notification and warning systems to inform the public after an earthquake, including AlertSF, the city’s text and email emergency alert system, social media, traditional media and perhaps, the Wireless Emergency Alert system.
