We have a mystery, locally. about 12 pm, many people felt/heard a boom and shaking. some people reported that is was followed by a high pitched whine. the area that seems to have gotten the worst effects was lake jackson, about 12 miles from us. some people as far as alvin (about 35 miles away ne), and brazos bend state park, (about 30 mi n) said they had experienced it also. more recently, someone said that it had been reported as far away as cypress, (80 m n), and porter tx, (81 m ne), although those are unsubstantiated and single reports, as opposed to the hundreds of people who have been blowing up local facebook threads. police have checked all local chemical plants, all possible companies that place explosions to map geologic stuff, nothing. no natural gas explosions in residential areas. no major fires. our only local paper has a thread going on their website, no news of what might have caused it. one of the houston news channels sent a reporter, and it was treated about as credibly as a santa sighting. (country hicks imagined feeling stuff). so far, we have a mass delusion. hundreds of people in the area, especially in lake jackson, felt their houses shake, and heard a loud rumble like thunder, although skies were clear. a friend in detroit, tx, about 350 miles north, read my post on facebook, and said that at about 11:30 am she had heard a loud and odd rumble of thunder, and even brought it to her husband's attention. they, also, were under clear skies.