People from Del Mar to Chula Vista took to social media Wednesday afternoon to report a “boom” that shook doors and startled pets, leading many to speculate that the region had experienced a short, mild earthquake.

Posts on Twitter and Facebook described a loud boom, accompanied by shaking doors and cabinets.

However, that is unlikely to have been the cause of the phenomenon, said Paul Laustsen, a U.S. Geological Survey spokesman.

“The last earthquake in the vicinity was at 4:16 a.m.,” he said during a phone interview Wednesday.


One military official suggested an ongoing exercise at Camp Pendleton could be the source. Artillery fire appears on a noise advisory for the base today, however, a base official said the exercise was canceled.

Laustsen suggested the reported effects indicate a sonic boom, and referred people to the USGS sonic boom information page.

San Diego-base Naval Air Forces said none of the Navy’s aircraft were the source of the boom Wednesday. Marine Corps officials from the MCAS Miramar-based 3rd Marine Aircraft Wing said it is also not aware of the source of the boom.

“While we are aware of media reports of a possible sonic boom, no 3rd MAW units have reported one in San Diego air space,” the statement said.


A similar mysterious sound in 2012 that military officials denied being involved in turned out to be Navy jets operating off the coast performing for embarked family members on the carrier Carl Vinson.

Although the carrier Abraham Lincoln is in the eastern Pacific Ocean with embarked family members now, its public affairs officer, Lt. Cmdr. Jesus Uranga, said in an email no similar demonstration took place the time of the reported event Wednesday.