For the third time since February, a mysterious “skyquake” rattled San Diego County and Tijuana; authorities say it wasn’t an earthquake

For the third time since February, a mysterious boom was heard and shaking felt Tuesday night by residents across San Diego County.The latest mystery phenomena — sometimes referred to as a skyquake — was reported just before 8:20 p.m. by residents as far south as Tijuana, as far east as El Cajon and in San Diego neighborhoods in the southeast and coastal areas, as well Linda Vista, Clairemont and Tierrasanta.A similar incident shook the region on Feb. 16. At the time, the United States Geological Survey tweeted that the shaking wasn’t an earthquake “but it may have been a sonic boom which are not too uncommon” in San Diego.About three weeks later, on March 10, residents across the region again reported a similar shaking and loud boom, though no earthquakes were reported.



“Yes, I heard it,” Gloria tweeted. “No, I don’t know what it was. I’ll share if I get any information. Get vaccinated if you haven’t yet.”



Though fewer residents in North County reported hearing the noise or feeling the shaking, former congressional candidate Ammar Campa-Najjar posited that the source may have been Marine Corps Base Camp Pendleton, which posted a noise advisory on Facebook earlier this month reporting that live-fire artillery training would be conducted June 5 through June 11, and last as late as midnight.