Strange rumblings were reported from Chula Vista to Oceanside around 12:45 p.m. Friday, June 29th 2012.
The mystery sound has been credited to military activity off the coast:
“San Diego, it looks like the boom that was heard and felt today was likely due to some aircraft associated with the USS Carl Vinson (CVN 70) family day cruise. As part of a flight demonstration two F/A-18 aircraft went supersonic about 35 miles off the coast. Sorry for any inconvenience this may have caused. — LT Aaron Kakiel, media officer.”
Oddly enough, there was no evidence of chaff on weather radar, as was the explanation of a mysterious boom reported near San Diego early this year. Chaff is a material emitted during military exercises.
Whales In Space has reported on mysterious booms before, including a cluster heard in Colchester IL, Portland OR, and Bellingham WA.