Magnitude 3.5 earthquake reported near Ontario airport, rattling Southern California
A magnitude 3.5 earthquake rattled a swath of Southern California Tuesday, causing light or weak shaking to be felt across the Inland Empire, as well as parts of Los Angeles and Orange counties.
The epicenter of the earthquake, which struck at 12:56 p.m., was less than a mile south of Ontario International Airport, near the corner of Francis Street and Carlos Avenue. An earlier estimate of the earthquake’s magnitude was 3.1.
People reported feeling the earthquake as far away as in eastern Los Angeles County and northern Orange County.
People may have felt “light” shaking closest to the epicenter, such as in Ontario, Upland, Chino and Montclair, as defined by the Modified Mercalli Intensity Scale, according to the USGS. Generally speaking, “light” shaking rattles dishes, windows and doors, and can cause walls to make cracking sounds. Some might experience “light” shaking as feeling like a heavy truck has struck a building.
The quakes, of magnitudes 3.5 and 3.9, occurred within about a half hour of each other. Shaking was felt as far away as Los Angeles, Orange County and San Diego County.
“Weak” shaking may have been felt in places like Pomona, Claremont, La Verne, Rancho Cucamonga, Fontana, San Bernardino, Rialto, Colton, Riverside, Jurupa Valley, Eastvale, Norco, Corona and Yorba Linda. “Weak” shaking may only be felt by a few people who aren’t moving, and if it is felt, might feel like a truck is passing nearby.
There have been three other nearby earthquakes — all in Ontario — of magnitude 3 or greater in the past month. On Saturday, there was a magnitude 3.1 earthquake, about 4.3 miles to the northeast of Tuesday’s temblor.
And three Saturdays earlier, there were earthquakes of magnitudes 3.5 and 3.9, separated by about half an hour, on Sept. 7. Those earthquakes had an epicenter close to the intersection between the 60 freeway and Archibald Avenue.
Other parts of Southern California have seen a number of moderate earthquakes in the past month. The Malibu area has experienced seven earthquakes of magnitude 3 and greater in the past month, the largest of which was a magnitude 4.7 that occurred on Sept. 12. That quake was felt widely enough that it startled television news anchors broadcasting live at KTTV-TV and KABC-TV.
The most recent Malibu-area earthquake occurred on Saturday, a magnitude 3.2, offshore of the city, about 6 miles southwest of Point Dume.
In early September, there were also a pair of modest earthquakes off the Rancho Palos Verdes peninsula. They involved earthquakes of magnitude 3.1 and 3.2, striking on Sept. 2 and Sept. 6, respectively, about 12 miles southwest of the Point Vicente Lighthouse.
An average of 234 earthquakes with magnitudes between 3.0 and 4.0 occur per year in California and Nevada, according to a recent three year data sample. But this year, Southern California has been unusually busy with earthquakes.
The earthquake occurred at a depth of 3.5 miles.
Did you feel this earthquake? Consider reporting what you felt to the USGS.
Are you ready for when the Big One hits? Get ready for the next big earthquake by signing up for our Unshaken newsletter, which breaks down emergency preparedness into bite-sized steps over six weeks. Learn more about earthquake kits, which apps you need, Lucy Jones’ most important advice and more at latimes.com/Unshaken.
An earlier draft of this story was automatically generated by Quakebot, a computer application that monitors the latest earthquakes detected by the USGS. A Times editor reviewed the post before it was published. If you’re interested in learning more about the system, visit our list of frequently asked questions.
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