Residents of the Southern California city reported the latest puzzling boom at 11:36 a.m. on Tuesday, Dec. 28, immediately taking to social media to ask what happened.
“What was that boom just now in San Diego?” asked one person on Twitter.
“Loud boom in San Diego, near the airport. What was that?” asked another.
“By coincidence, I had just walked outside when a compression wave hit — I saw the windows on the apartment next door get compressed, and it was big enough that it brought another neighbor out to see what was going on,” read a Twitter post.
Several people thought it might be a sonic boom. “Sonic boom not earthquake in San Diego,” speculated one post. “Another day, another mysterious, house-rattling sonic boom in #SanDiego,” a resident wrote on Twitter.
“San Diego is cool bc im like oh wow just felt an earthquake but no actually it was a sonic boom,” read another tweet. Reports of the mystery boom came in from the Mission Hills and San Carlos neighborhoods of San Diego, as well as Santee and El Cajon in eastern San Diego County, KNSD reported.
The Volcano Discovery site also received reports of shaking in San Diego, listing the incident as “unconfirmed.”
The U.S. Geological Survey shows no earthquakes in the area at that time. The FAA and military branches contacted by KNSD also said they were not aware of any sonic booms created by aircraft at that time.
“Weird things happen all the time, and we find perfectly scientific explanations for them,” Robert DeGroot of the USGS told the station. “We find things that pique our interest and then we figure it out.” San Diego residents reported similar mysterious booms in early December, KSWB reported.
Another mysterious boom shook the city in June, possibly from artillery training exercises at nearby Camp Pendleton, McClatchy News reported. Similar incidents also took place in February and March, The San Diego Union Tribune reported.
**By Don Sweeney