April 9, 2014, 4:23 p.m.

Some residents in Long Beach and the north Orange County coast reported feeling and hearing what some thought was an earthquake Wednesday afternoon.

But Caltech seismologist Kate Hutton said no earthquakes were reported in the area during the time the shaking was reported.

"It's not an earthquake. It's probably an offshore sonic boom," Hutton said.

Federal Aviation Administration spokesman Ian Gregor said any sonic boom would come from a military aircraft.

"Civil aircraft do not exceed the speed of sound, so any sonic boom would come from a military aircraft," he said. "Military aircraft do not fly supersonically in civilian airspace; they would only do so in restricted military airspace out over the ocean."

[Updated at 4:23 p.m. PST, April 9: Scott Conner, who lives in the Big Rock neighborhood of Malibu, said he was convinced the shaking he felt just after 1 p.m. was a quake.

He said the shaking was so intense one of his computer monitors would've tipped over if he wasn't there to steady it.

"I had to put out my hand to keep it from tipping over," Conner said in a telephone interview.

"I thought it was the biggest quake I've ever been in…. This thing was big, big," he said. "The whole house just lifted.

"I've been around air force bases. I know what sonic booms are. There was no boom, either," Conner said.]