A 4.4 magnitude earthquake shook Santa Rosa residents Tuesday and on Wednesday, the U.S. Geological Survey issued a somber reminder that the next quake could be much larger and do serious, extensive and widespread damage.
“Actually, if you look at the San Francisco Bay Area in general, the probability of a magnitude 6.7 quake or greater in the next 30 years is actually 72%. So it's more likely than not,” said Andy Michael, a geophysicist with the USGS.
That’s based on seismometers and historical records of earthquakes, as well as studies of their faults.
“Basically, we think the past is a good hint to the future,” said Michael.
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A more immediate earthquake notification was sent from California’s Early Warning Alert, which notified 400,000 people of the quakes, mostly through Google and Android devices. iPhone users could get the alert from the My Shake app.
“The California Earthquake Warning system, the country’s first publicly available system, delivered,” said Jose Lara, Seismic Hazard Branch Manager with California OES.
People closest to the epicenter may have gotten the alert during or right after the quake hit, not much help there.
But people farther away had time to respond. Vallejo received an 11-second heads up. Oakland, 19 seconds.
“We received a lot of reports about people being able to take protective action such as drop, covering and hold on,” said Lara.
The state's Earthquake Warning System is a work in progress. It hopes someday to have an integrated warning system that can offer automatic gas and water shutoff at your house, and automatic restarting of elevators at commercial buildings.
