Sonic Boom Research San Diego, CA, & Loudest/Longest I've Ever Heard
Carlsbad 2 blocks from the beach carlsbad Village area! It lasted about 15 seconds the whole apartment building 2 stories was rattling and the ground and air seemed very loud roaring but no ground shake like a traditional earthquake.. It was about an hour before a 6.3 earthquake in China. I see gas bubbles coming up in the beach water near the waves quite often too. It's really nothing weird, if it is earthquake-related. We're all around it. SDG&E even knows the beaches release natural gas all the time. But I'd like to know if sonic vibrations increase with distance and or when they begin to decrease and eventually stop at mountain ranges we have in So Cal. But someone said they were felt/heard in vegas.
And according to news articles, navy spokesperson's have said the distance of booms felt could be up to 50 miles. Evidently, the navy was out about 30 miles when their pilots are said to have been flying. +mach1 speeds
Boom intensity is greatest directly under the flight path, progressively weakening with greater horizontal distance away from the aircraft flight track. Ground width of the boom exposure area is approximately 1 statute mile (1.6 km) for each 1,000 feet (300 m) of altitude (5 m/m); that is, an aircraft flying supersonic at 30,000 feet (9,100 m) will create a lateral boom spread of about 30 miles (48 km), or at 10,000 meters a spread of 50 kilometers.
According to wikipedia, The "boom" is experienced when there is a sudden change in pressure, so the N-wave causes two booms, one when the initial pressure rise from the nose hits, and another when the tail passes and the pressure suddenly returns to normal. This leads to a distinctive "double boom" from supersonic aircraft. When maneuvering, the pressure distribution changes into different forms, with a characteristic U-wave shape.
The sound was felt or heard in all corners of San Diego County By R. Stickney, Lauren Steussy and Monica Garske Friday, Jun 29, 2012 | Updated 7:02 PM PDT http://www.nbcsandiego.com/news/local/Strange-Sound-Reported-San-Diego-Coastline-Mystery-Sound-160873565.html
By Nicole Darling http://www.sandiego6.com/news/local/Shaking-Felt-in-San-Diego-160876045.html?skipthumb=Y#
Story Published: Jun 29, 2012 at 1:09 PM PDT
From as far east as Alpine and west to Coronado, residents of San Diego County reported feeling a boom and slight shaking around 12:45pm today.
Fox 5 Reporter http://www.fox5sandiego.com/news/kswb-navy-clears-up-sonic-boom-mystery-20120629,0,4466934.story
The planes were reportedly operating about 30 miles offshore.