Moments after a mysterious Boom was heard in San Diego, people started sending messages out via social media asking “what was it?”
NBC SanDiego received a number of reports from residents of a shaking or a loud noise just before 9 a.m.
The U.S. Geological Survey has not reported a nearby earthquake.
Officials at MCAS Miramar said the noise or vibration was not a sonic Boom from their aircraft.
San Diego State University Professor Emeritus Pat Abbott felt and heard it and stepped outside his home.
“The only time you hear an earthquake is when you’re directly over the epicenter,” Abbott said.
In his opinion, the sound was atmospheric.
Thunder and lightning were in the forecast Friday, but NBC 7 Meterologist Jodi Kodesh looked into it and said there weren’t any storm cells near the area producing thunder and lightning at that time.
When lightning strikes, the discharge of energy can be felt 5 to 10 miles away as a rumble or a boom, Kodesh said.
The closest rumble of thunder at the time would have been north of Los Angeles.
Sometimes, a military exercise known as chaff can cause a similar sound.
Strips of metal foil dropped by an aircraft are used to temporarily hide an aircraft from radar detection.
The National Weather Service couldn’t confirm if the sound was a result of chaff and an MCAS Miramar official told us he was not aware of possible chaff in the area.