In the wake of a pair of earthquakes that shook Southern California Thursday and Friday, local disaster experts are encouraging San Mateo County residents to take steps they say could stem the damage that could result when the “next big one” hits closer to home.
Ole Kaven, geophysicist at the U.S. Geological Survey’s Earthquake Science Center, noted the seismic activity recorded near the town of Ridgecrest in the Mojave Desert last week has no direct impact on the seismic activity in the Bay Area. But he acknowledged the type and impact of the Southern California earthquakes are similar to what could transpire on Bay Area fault lines.
Kaven said the USGS is monitoring all of the Bay Area’s fault lines, including the San Andreas Fault which runs through the Bay Area on its way from the Salton Sea in Southern California to the southern coast of Oregon as well as several other faults he said are capable of seismic events of a magnitude similar to the Ridgecrest earthquakes.
Because of the length of the San Andreas Fault, it is capable of generating large earthquakes like the one in 1906 that severely shook the Bay Area, said Kaven, who noted USGS experts estimate there is a 22% chance the San Andreas Fault will generate an earthquake of magnitude 6.7 or larger in the next 20 or 25 years.
Kaven added the Hayward Fault, which runs along the base of the hills in the East Bay, has an even higher possibility of a rupture, with a 33% chance of an earthquake of magnitude 6.7 of larger in the next 25 years. Among the other fault lines that could affect Bay Area residents are the Calaveras, Greenville and Concord-Green Valley faults, he said.
Kaven acknowledged his office receives many inquiries following an earthquake, which he views as an opportunity to remind Bay Area residents and beyond they live in earthquake country and should take steps to prepare themselves for an event that could hit closer to home. Whether it’s equipping themselves with an emergency kit or figuring out how to turn off their home gas mains, which is recommended after shaking has subsided, the preparation residents take on before an event can significantly reduce the damage they sustain should a disaster occur, noted Kaven.
“I think this is a great reminder we live in earthquake country and an event like this is likely to happen in our lifetimes in the Bay Area,” he said. “We can prepare for this to reduce the losses we might sustain in such an event.”
Kevin Rose, Office of Emergency Services manager within the San Mateo County Sheriff’s Office, said officials learned from the 2014 earthquake in Napa — which struck in the middle of the night — that keeping a pair of shoes and a flashlight under one’s bed can help minimize injury and help preserve already-stretched resources at hospitals.
In the event of an earthquake, Rose said the county’s network of first responders would focus on distributing USGS information to residents so they understand what happened and also to be prepared for the possibility of aftershocks, which he noted can continue to seriously damage infrastructure after the first earthquake hits.
After they assess their own health and that of their families, Rose said first responders work to ensure all emergency equipment that might be needed following a disaster is moved outside the area to ensure it can be transported to where it’s needed most, even if roads and other transportation infrastructure are damaged.
Kaven acknowledged the challenges of estimating how much damage an earthquake might cause in a given area, noting some tremors can be more shallow but result in significant ground motion and shaking whereas other, more deep earthquakes can cause less damage. He said the shaking people feel depends on how close they are to an earthquake’s center and the type of rock they are on and that most people feel shaking and see damage with an earthquake of magnitude 4 or higher.
Rose said law enforcement and fire officials make regular checks on their communities and noted many communities have practiced strategies for checking on others in the event of an emergency. Rose said first responders are also focused on maintaining the county’s critical infrastructure in the event of a disaster with an eye for maintaining as many of the county’s safety net services, such as health and meal services, as possible.
Though a full list of items residents can consider storing in case of emergency is available on SMCReady.org, Rose emphasized the importance of storing the essentials, meaning enough bottled water, food and medicine for three to five days.
Rose added cardiopulmonary resuscitation, or CPR, and first aid education can prove useful and said radios with fresh batteries can help residents tune into local stations providing updated information on what is happening, which he said can help keep 911 lines open to take calls from those experiencing emergencies.
Rose emphasized the importance of looking after older adults or those with disabilities to ensure they are safe immediately following a major disaster. He also commended the county’s 20 cities for developing their own emergency protocol that is practiced and refined regularly.
“They may be more susceptible to the elements,” he said, of older adults and those with disabilities. “A ready community is a more resilient community.”
To gauge the probability of earthquakes along fault lines throughout the state, Kaven said geologists study the instrumented records of earthquakes and also study the faults in the field to estimate when earthquakes that predate instruments might have occurred. He said USGS works with local agencies to spread the word about earthquake preparedness and develop seismic hazard maps and other tools that can help residents imagine what might be expected in terms of ground shaking and losses in an earthquake.
“Our memories are pretty short and we forget that earthquakes happen in our backyards,” he said.
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