4.2-magnitude quake wakes San Francisco Bay Area in California, seismologists say

A pre-dawn 4.5-magnitude seismic event rattled the San Francisco Bay Area and the Monterey Bay region in California, according to the United States Geological Survey.

The 6-kilometer deep quake struck 3 kilometers from Aromas, approximately a 72-kilometer drive south from San Jose, at 2:47 a.m. Sunday, Sept. 29, the USGS stated.

Over 3,000 individuals from locations as distant as Fresno and Kerman had indicated feeling the tremor to the agency by 6:45 a.m.

"My feline companion leaped in utter panic," one individual posted on X, previously recognized as Twitter.

"Undoubtedly experienced that in Gilroy! The notification arrived just as the shaking ceased," another person commented.

"Wow... that was a significant one," read an additional X post.

Essential earthquake information

Magnitude quantifies the energy discharged at the earthquake's origin, according to the U.S. Geological Survey. It has supplanted the outdated Richter scale.

Hurricane Helene Devastates Southeast: Dozens Dead, Millions Powerless

Seismic events between 2.5 and 5.4 magnitude are frequently perceived but seldom inflict substantial damage, as per Michigan Tech. Quakes below 2.5 magnitude are rarely noticed by the majority of people.

Earthquakes' abrupt, swift shaking can trigger fires, tsunamis, landslides or avalanches. They may occur anywhere, but they're most prevalent in Alaska, California, Hawaii, Oregon, Puerto Rico and Washington, as stated by the Department of Homeland Security.

Should an earthquake occur, it's advisable to safeguard yourself immediately. Here are recommendations from experts:

If you're in an automobile: Stop and pull over. Engage your parking brake.

If you're in bed: Turn face-down and shield your head with a pillow.

If you're outside: Keep away from structures. Avoid going indoors.

If you're inside: Remain there and don't run outside. Stay clear of doorways.

The most effective method to protect yourself during an earthquake is to drop, cover and hold on, authorities advise.

"Regardless of your location, lower yourself to your hands and knees and grasp something sturdy," officials recommend. "If you're utilizing a wheelchair or walker with a seat, ensure your wheels are locked and stay seated until the tremors subside."

Be certain to shield your head and neck with your arms, and seek shelter under a robust table if possible. If no shelter is available, crawl to an interior wall away from windows.

Once beneath a table, authorities suggest holding on with one hand and being prepared to move with it.

"Serious hazards can arise following an earthquake, such as structural damage, gas and water line leaks, or fallen power lines," officials caution. "Anticipate aftershocks to follow the primary shock of an earthquake. Be ready to Drop, Cover, and Hold On if you experience an aftershock."