Napa Valley Earthquake, Aftershocks Rock San Francisco Bay Area, Officials Urge Preparation For More Tremors

Aug 25, 2014 04:46 PM EDT

After a moderately strong earthquake shook the San Francisco Bay area early Sunday morning, Northern Californians fear the threat of more, possibly devastating, tremors.

According to CBS News San Francisco, 170 people in the Napa Valley were injured and historic buildings were damaged as the earthquake hit. Gas lines and water mains across Napa, Sonoma and Solano counties were also ruptured, leading to multiple fires and loss of electricity across the area, causing Gov. Jerry Brown to call for a state of emergency in Southern Napa County. 

Following the earthquake, nearly 100 aftershocks were recorded, making it the largest to hit the Bay Area since the 6.9 magnitude Loma Prieta quake nearly 25 years ago.

The earthquake measured a 6.1 magnitude before being revised to 6.0, and then upgraded back to 6.1.

Those critically injured include six adults and a child. The child was airlifted to another hospital for specialist care after being severely injured when a fireplace collapsed.

"This is the sort of earthquake we expect to happen in California," said U.S. Geological Survey seismologist Lucy Jones.

"It happens somewhere in the state on average once every few years. When they happen near people, we get damage. The damage that I'm seeing is completely predictable and could have been preventable but we haven't as a society chosen to do that."

Emergency response officials also said preparedness is crucial in dealing with an earthquake.

"We're predisposed to earthquakes and fires in this area," Los Angeles Fire Department spokesman Shawn Lenske said. "So knowing that and knowing how to prepare is the most important thing."

September is National Preparedness Month, Lenske said, which is a federal effort to "be disaster aware." The website ready.gov urges the public to be informed, make a plan, build a kit and get involved.

"We (LAFD) have a standing plan if we do have an earthquake because we have had them in the past," Lenske said. "And we maintain our plan once we do have an earthquake to utilize proper care."

The County of Los Angeles Office of Emergency Management, Red Cross and other state and federal agencies sent out several messages via Twitter reminding the public to drop, cover and hold on during an earthquake, as well as links to register for the state's biggest earthquake drill, the Great California ShakeOut, held annually at 10:16 a.m. Oct. 16.

However, though California has seen an unusually high number of earthquakes in 2014 compared to the average in 1979, experts say it could just be a statistical anomaly.

"It's such a small sample and short time frame, let's not get alarmed," said CNN meteorologist Sean Morris.

As far as when the "Big One" will occur on the San Andreas fault (the last one occurred in 1857), experts say there is no indication it will happen anytime soon, as Sunday's earthquake was not on that same line.

"I don't think we can make any connection on that," CNN meteorologist Chad Myers said. "This is on a different fault -- still part of the same system, still the plates are still shifting from California, the North American Plate and the Pacific Plate."

However, because "moderate-sized, potentially damaging earthquakes could occur in California at any time," Rep. Adam Schiff, D-Burbank urges locals to remain prepared as "Preparation and early warnings can be the difference between life and death."