I used to live on Columbia Road (15 years) and am familiar with the rock quarry blasts. I now live in Wilmington, NC. What I felt yesterday, and have felt and heard in the past in Wilmington, are not the same as the rock quarry blasts. What we experienced here yesterday happened just after 10:00 am. What was felt in Columbia County was at 10:30. The speed of sound in air is about 12 miles per minute. Evans is about 300 miles from Wilmington. The numbers work out this may have been a huge sonic boom. It was probably too large to be military craft. I am working on a theory that huge atmospheric pressure differentials are being created just off the coast, basically when high pressure and low pressure meet suddenly and the pressure differential has to resolve itself immediately.
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