San Francisco has been infamous for devastating earthquakes in its history, but Sunday morning’s magnitude-6.0 temblor near Napa that rocked much of the Bay Area appears to have left The City mostly unharmed.
Residents throughout the Bay Area were rattled awake when the largest earthquake to hit the Bay Area in nearly 25 years struck at 3:20 a.m., about six miles southwest of Napa. The quake sent dozens of those in California’s wine country to hospitals, ignited fires, damaged historic buildings and knocked out power to tens of thousands, authorities said.
However, no damages or injuries were reported in San Francisco, according to the Department of Emergency Management. Muni service remained unaffected Sunday, and the two major home sports games for the Oakland A’s and San Francisco 49ers took place as scheduled. And it appears no one lost power from the event in The City, according to PG&E.
Still, the earthquake should serve as a wake-up call to San Francisco, which has seen such notorious quakes as those in 1906 and 1989, said Patrick Otellini, The City’s director of earthquake safety.
“It’s been a long time since we’ve had some shaking of this level in the Bay Area,” Otellini said. “The irony’s not lost on me that we’re only several months away from 25th anniversary of Loma Prieta. [The Napa earthquake] is a wake-up call that we should be thinking about it.”
San Francisco escaped damage for a number of reasons: The earthquake is considered moderate in size, and its energy was directed northeast, away from The City and much of the Bay Area, said Janiele Maffei, chief mitigation officer with the California Earthquake Authority.
“The message is that sometimes Californians are emboldened when there’s an earthquake somewhere in their neighborhood,” Maffei said. “In reality, the earthquake was moderate and far enough away that there wasn’t sufficient ground shaking to cause damage [in San Francisco].”
That’s unlike the magnitude-6.9 Loma Prieta quake that hit on Oct. 17, 1989, which rattled San Francisco much more severely and was 10 times stronger at its epicenter near Santa Cruz than Napa’s temblor.
“This is not what a big earthquake feels like,” said Matt Springer, a UCSF professor who lectures on earthquake-safety measures at medical centers and libraries in The City. “It’s just closer to [a significant event] than these tiny earthquakes that we’ve felt over the years.”
Mayor Ed Lee said that Napa’s temblor is a reminder for residents to always be prepared for a catastrophic event.
“We know disasters, whether it is an earthquake, tsunami, or something human made, can happen at any time with little or no warning,” Lee said in a statement. “That is why it is important to take steps now so we are ready for any emergency.”
San Francisco has implemented a number of seismic safety efforts over the years. In 1998, The City launched its Community Action Plan for Seismic Safety, a years-long analysis of potential earthquake impacts, as well as community-supported recommendations to mitigate such impacts.
The City in 2011 initiated its Earthquake Safety Implementation Program, a 30-year timeline to execute recommendations from the community action plan. In 2013, the Soft Story Ordinance was signed into law, requiring the evaluation and retrofit for multi-unit soft-story buildings within seven years, and The City is weeks away from a Sept. 15 deadline for owners or agents of notified buildings to submit screening forms to the Department of Building Inspection per the ordinance.
San Francisco is considered a leader in other seismic safety measures as well. A proposed ordinance that would call for The City’s 120 private schools to undergo seismic evaluations was re-introduced to the Board of Supervisors in July. If approved, the legislation would make San Francisco the first city in California to require private schools to be evaluated for earthquake safety.
City officials are also looking into a Façade Maintenance Program, aimed at reducing the risk of façade failure in earthquakes.
Meanwhile, the San Francisco Unified School District – which began its school year last Monday – will likely hold earthquake drills this week, district spokeswoman Gentle Blythe said.
According to the Northern California Earthquake Data Center, there is a 45 percent chance an aftershock of magnitude-5.0 or greater will hit the Bay Area this week.