Series of earthquakes shake Inland Empire overnight

Residents living in the Inland Empire may have been woken by a series of earthquakes that shook the area during the early morning hours on Wednesday.

The first was a 3.5 magnitude quake that struck at 1:02 a.m. about 4.6 miles southeast of Ontario at a depth of roughly 4 miles, according to the U.S. Geological Survey’s event report.

Twelve minutes later, a second quake struck the same area. This one also registered a 3.5 magnitude and was 4.4 miles southeast of Ontario at about the same depth as the first temblor.

Sam Osman, who works in Ontario, said he felt both quakes. 

“I work in a warehouse … you could see all the little things shaking, but other than that, it wasn’t anything major … I’m used to it. I’m from California, you know.”

The third and strongest of the overnight earthquakes rattled the Lytle Creek area further to the north at 2 a.m., recorded as a 3.7 magnitude quake with a depth of more than 6 miles, according to the USGS event page.

A smaller 2.1 magnitude earthquake hit the same area about 11 minutes later and another 2.5 magnitude temblor struck at 5:25 a.m.

Wednesday’s shaking follows a 3.5 magnitude earthquake that struck the Rialto area around 4:55 p.m. on Tuesday.

Last week, another series of quakes also rattled the Inland Empire, including a 4.3 magnitude temblor recorded near Rialto.

There have been no reports of damage or injuries.

Thousands of earthquakes are recorded in California each year, but the vast majority are extremely minor. Several hundred reach a magnitude of 3.0, and only about 15 to 20 reach a magnitude of 4.0 or greater, according to the USGS.   

In North America, only Alaska records more quakes per year than California. 

What to do in an earthquake

During an earthquake, knowing the proper steps to protect yourself and minimize injury is crucial. The California Department of Public Health (CDPH) provides detailed guidelines on what to do during such events. Here are the key points:

Drop: Immediately drop down onto your hands and knees. This position prevents you from being knocked over and allows you to stay low and crawl to safety if necessary.

Cover: Use one arm to protect your head and neck, and if possible, take shelter under a sturdy table or desk. If no shelter is available, get down next to an interior wall away from windows. Stay on your knees and bend over to protect vital organs.

Hold On: Hold on to your shelter until the shaking stops. Be prepared to move with your shelter if it shifts.